Well, I've got a Bluguitar AMP1 (as of last November) as well as a Rivera Clubster 45 and a Cornford Harlequin. I just joined the site today or I'd have chipped in sooner.
It's pretty good as a live amp for all the reasons you might expect - light, small, loud enough to fill a 200+ person venue without going through the PA, easy to set it up to be heard in the band mix. I'm not intending to use the Rivera for gigs any more and thinking of selling it. The AMP1 is much easier to set up for live use. The audience hears a decent sounding guitar tone that is totally acceptable for the purpose.
Let's face it, most audiences in small, noisy venues don't hear the finer things in your tone too well. Most people usually can't tell if a recorded guitar is actually a guitar plugin, either. To me, the AMP1 sounds good in the band. If it sounds good, then it is, no matter what technology is being used. Even so, just like any amp, there are tones that are great at domestic levels which sound poor when used at higher volumes and get lost completely in a band mix. Sometimes the tones that sound good in the mix aren't so pleasing when heard in isolation, either.
The preamp is solid state, but definitely analogue, not modelled. It has 4 voices that can be fine-tuned to balance and gain-stage against each other. I particularly like the clean sound (very organic, Fender-ish) and the vintage sound (early low gain Marshall-ish). The power amp has a 'mini' valve which shapes the sound before it (I'm guessing here) goes into a Class D amp to get the volume. Turning down the volume control causes the sound to clean up nicely, BTW. The entire signal path is analogue unless you use the digital reverb, which adds its 'wet' mix into your dry sound. I rather like it, a simple 'spring' type sound similar to a TC Hall Of Fame.
I bought it to play live. But... I'm now toying with using it for my songwriting demos. Here's why:
The amp can run without a speaker load straight into an audio interface. There is some speaker emulation built in that isn't as good as a Two Notes CAB, but it's not bad if you add Space Designer (I'm using Logic Pro) and a free IR file. I've been having trouble getting the Logic guitar amp plugins to sound as good as AMP1 does, which is probably my inexperience with DAWs, but I just want to record demos - I'm not making Dark Side of the Moon (other recordings are available...).
So, hope this is helpful to some. I'm a fan. Any questions, do ask and I'll try to answer.
Cheers, Norman