When reamping, the sound you get back is exactly the same as when you first played it, assuming you're using the same amp. If its not, you've done something wrong somewhere.
What do you mean when you say the original "recording was quite thin"?
Your DI signal is probably not beefy enough, or is too beefy. This affects the output of the Kemper. You need to set it to a level that the signals are balanced both when recording as well as reamping, i.e. the signal should be the same strength
How are you recording your "original"? It sounds like it might have some sort of stereo effect or something on it.,.?!
Try adjusting clean sense. Set it the same way as if you were using your guitar, except with SPDIF as the signal. This should give you a robust tone to send through the Kemper. Any changes you are hearing are likely on account of the DI signal not being captured accurately, or not being fed back the right way.
Nightlife, I've tried adjusting clean sense it doesn't appear to make a lot of difference unless I'm doing it wrong?
There was a slight chorus on the original, I'll test with the chorus off but I cant see that the whole tone would change that radically.
It sounds to me like an electric going straight thru the desk but I have checked that cabs/stacks etc are on.
Cheers,
Mike
Do you understand you need to be recording literally your dry guitar for reamping purposes? If you're trying to reamp something thats already gone through some kind of preamp, results will be awful.
Lolololololololol 
No prob.
