I have to admit my utter gas for an axefx and kemper that made me look at what was possible with iOS modelling (since I was already using it for looping)
I'd defo start of small before grabbing a kemper or axe mainly because it looses a lot of value if you're not using it in a studio and live you're still lugging round a power amp and cab.
If you can survive with the PAs available, you have IEMs or you're mainly in the studio then go for it.
I personally have a lot of experience of getting my sound from a Di pedal etc, but nothing even now can beat the sound of a good valve amp behind you, and my iOS rig is the compromise of tone (of a big valve amp) over portability, it certainly sounds better than the modern amps I've tried and is effectively tiny.
A sansamp is a good starting point, if you can be happy with that then you'll be ecstatic with a Kemper