I thought it will be great for me as a backup but it will be just to at least have some sounds if my stage or rack stop working.
Missing the slots is already a problem but for me more missing some of the effects. Most of my sounds have the studio EQ included for example. With some other effects missing I can use maybe 10% of my current rigs as they are. Some I can't use at all (with Pitch Shifter for example).
I use about 120 performances live in rotation at the moment with up to 5 rigs each so changing all of them or creating them again from scratch is too much work.
So at the moment as it is it will be just a small amp if I play with others for fun or a very basic backup.
I hope they announce the (paid) upgrade soon. Otherwise I will send it most likely back within the 30 days.
Use case 1: High Functional Backup to full KPA
I think it would be OK with only 4 FX slots, but missing the actual EFX is a serious problem. In this use case, the idea is to get along with a lower spec'd device, but to have on-hand the original sounds you had in the full unit (with physical limitations as well as fx slot limitations). The work load is now to create custom rigs that approximate your full KPA rig. Doable, but not a home run in marketing IMO. Additionally, as some have stated, working pro's will likely have a full KPA backup. As used KPA's are going for under 1K right now, it seems like a tough sell to buy an $800.00 lower end replacement.
Use case 2: First time buyer of a small 3 button portable all-in-one guitar processor
I believe that the missing color LCD will make it a tough sell against the Line 6 Stomp HX. Yes, the player has advantages over the Stomp HX: Better tones, efx spill-over, free rigs via rig manager, etc. It just seems like it is a tough sell without the LCD. In my mind, I thought this was the biggest market for a 3 button device, so this is where I disagree with the lack of the LCD.
Use case 3: Amp module within a pedalboard
I hadn't really considered this in my original thoughts on a Kemper "mini", but there are some that this is how they roll. Ok, so in this use case, the musician has other efx pedals and the primary purpose of the KPA Player is to act as the amp tone. In this market, the main competitor is Tone X. Yes, it has considerably less EFX capabilities than the KPA Player, but when using it in a pedal board, I think that isn't a big issue. Tone X is considerably less expensive at $400 USD. In fact, it really makes a play for the first time buyer of a small 3 button portable all-in-one guitar processor by having some efx AND it has a minimal LED screen (better than nothing).
Use case 4: Small, inexpensive, backup for any high end rig
This is where I would likely buy. I don't gig for a living and have no desire to have a full KPA backup (both $ wise and size wise). Since I am quite taken with the KPA (I have a rack and FC), and I have more disposable income than most, I might decide on the Player, but where it would have been a slam dunk if it had an LCD, now I would defiantly go try out the ToneX and Stomp HX. In all 3 cases, this would be a "limp through the night" setup where I would try to get through with a clean, a crunch and a heavy tone. It would never be something I used all the time.
I don't think that it is unusual for people to think that KPA missed the mark here. It is an interesting mix of features. My personal belief is that Kemper was more worried about savaging their own market than they were about devastating someone else's market. I think a product having a decent LCD and 4 fx slots with a full KPA effects complement at $800 would have put a serious dent in Line 6 Stomp and Fractal FM3.
FWIW, I do product management for a living. I haven't researched this particular market (other than what I can see from competitive analysis), so there is always the possibility that information I am not aware of makes the KPA Player a more potent product than it appears to me.
Note: I don't believe for one minute that Kemper isn't going to sell quite a few of these. There will be plenty of people that want one in the near future. It won't be until the shoot-outs start taking place that people will start making longer term determinations of where the product lies in the market.