A "bad" guitar can sound good through the real rig as well.
If the question would be whether kpa introduces something different that may make different guitars (or different pickups, whatever we are interested in testing) sound more different than they would through a given, real guitar rig..
That is an interesting issue that can be tested. Generally speaking my impression is that nope, kemper profile is similar to real rig in that sense (also kemper's official stance), even though i feel string height/fret buzz can create the feeling that that subtle profiling innacuracies are exaggerated further.
All that said when I make profiles it is for particular guitars (and more so pickups) but more so due to dialing in the real rig differently each time to fit the pickup.
It's not different from a real tube amp IMO, you just have to find the right profiles or tweak your KPA to get the most of your 'crappy' guitar
I've been using chinese squiers on tons of recordings with tremendous success given the value or these sub 300€ guitars.
I think it just gets the most out of guitars because it sounds so good. It's always going to sound better than the same guitar through a Roland cube.
The KPA just like a cranked miked amp exposes sloppy playing and / or a poorly setup guitar.
I've become much more aware of my playing and setup since getting the Kemper. The quality of guitar is only as good as its setup and your playing.
I think it just gets the most out of guitars because it sounds so good. It's always going to sound better than the same guitar through a Roland cube.
not, if you profiled a Roland cube. 
I’ve used older digital guitar products that lessened the differences between different guitars - they made all guitars sound more similar than they would if they were played through a real amp.
The KPA does not do that - individual guitars sound just as different as they would through the amp that has been profiled.
I’ve used older digital guitar products that lessened the differences between different guitars - they made all guitars sound more similar than they would if they were played through a real amp.
The KPA does not do that - individual guitars sound just as different as they would through the amp that has been profiled.
Yeah - I bought the very first Line 6 modelling amp right after it came out and it used to really mask the actual guitar sound.
Yes- the AxSys, the AX2, the Vetta, and Vetta2 all did this. The Vox Tonelab series also did it, but, not as much as the Pod series.
I used all of those products, but kept going back to my Marshall. And, then I would try something new, and go back to the Marshall. Five years ago, I bought a Kemper. The pattern has been broken - with my Marshall in the KPA (and all those other amps), I don’t even shop for new amps anymore.
Same here. I have to admit I haven't fired up a tube amp more than a few times since I got it. Even then it was just to confirm that I'm not experiencing psycho acoustics, but the KPA always holds it's own.
In my experience the Kemper faithfully translates the sound of guitars just as well as any tube amp. That said where it has an advantage over a tube amp for cheaper guitars with perhaps poorly shielded pickups is in the ability to play at low volumes with "cranked" sounds and good grounding and lifts built right into the unit. This means for instance far less chance of microphonic feedback and less hum.
Honestly though I've not encountered any guitars built that cheaply in absolute yonks. These days even the cheapest of guitars seems to be pretty solid when it comes to build quality and electronics and outside of feel issues I'd have no problem gigging one.
I have a few guitars that I use with the Kemper. The first thing I noticed about the kemper was how different all my guitars sounded. So much so that it really frustrated me to the point of buying a new one. All my guitars sound great on kemper except one. That guitar sounds fine on my tube amp though. Guessing that I may have a tone knob that is out of whack.
.
In my experience, the sound of a bad guitar is usually better with a Kemper. (As with almost all guitars). Sloppy playing could have the opposite effect. Errors are also transmitted more precisely.
But the Kemper can't turn a bad guitar into a good one.
The Kemper cannot influence transient response, sustain, playability, tuning stability and quality of PU's.
BTW: However, the price does not say all about the quality of a guitar. 
In my experience, the sound of a bad guitar is usually better with a Kemper. (As with almost all guitars). Sloppy playing could have the opposite effect. Errors are also transmitted more precisely.
But the Kemper can't turn a bad guitar into a good one.
The Kemper cannot influence transient response, sustain, playability, tuning stability and quality of PU's.
BTW: However, the price does not say all about the quality of a guitar.
Better with a kemper compared to profiled source tone?
Or better than the guitar through, say, an old Roland cube?
I started playing electric guitar thru a lousy tube amp a guy in my area had assembled, and soon afterwards I bought a solidstate amp cause I couldn't afford a Marshall. Then came multieffect devices and hybrid (solidstate with a tube) preamps which provided a better distortion and which could be used at bedroom levels, and soon afterwards digital gadgets like the Pod, you name it. The amps had always enhanced any sloppiness, whereas the new gadgets could hide it somewhat. And all guitars sounded a bit similar thru most presets. Now, with the Kemper, I feel the nuances and differences are brought back, as if I were using a "real" amp. For better and for worse. You can make the controlled sloppiness of blues playing more transparent than with earlier digital stuff. The subtleties of articulating notes this or that way are there, as well as undesired ghost notes, rattles, buzz or plain mistakes. Gibsons and Fenders, high versus low action, etc You notice the differences. A bad guitar cannot sound as great as a boutique one, but we all know some players can make any guitar sound great. But I doubt these guys would sound terrific thru some cheesy solidstate or digital distortion of the early days. So, I think you can get away more easily wirh a cheap guitar than with a bad amp, be it tube or digital.
I play mainly Tom Anderson electrics. Its realy big difference in soundcharactristics from guitar to guitar. It is huge difference going from my TA strat to my TA Hollow shortscale telecaster! The Kemper react like any oyher amp regarding different guitars setup and pickups!
It seems like its bigger difference in different pickupsettings on my Kemper than on my favourite tube amp.
I think it faithfully translates what's fed into it. In that respect, I really do think playing a great guitar into a Kemper profile is better than playing a so-so guitar into a Kemper profile, in terms of tone, sustain, etc.
Like our mix engineer said: you can't polish a turd 
So of course the guitar should sound good and should fit to the amp, settings and genre.
So thats also true for the choosen kemper profile.
Fortunately there are many guitars on the market, which sounds good for a nice price.
If possible take your kemper and go to the next music store and test different guitars. You will see...
The KPA just like a cranked miked amp exposes sloppy playing and / or a poorly setup guitar.
I've become much more aware of my playing and setup since getting the Kemper. The quality of guitar is only as good as its setup and your playing.
Yeah I used to use amp sims, which I was never happy with and when I purchased a Kemper...did it reveal how sloppy my playing had become or what? I had to start practice again.
