I bought this for a buddy of mine, to replace his tube amp for a few gigs. Sadly, the GE 200 did not do a great job - through headphones, the presets sound ok at best and through PA, they sound really synthetic, fake and there's tons of bass and treble.
In the band that I play with, I am the second guitarist and I rock a tube amp (120w 6L6 american-voiced amp), along with a 212. We tried using a preset that's supposed to sound close to it, then tried making our own with the software found on their website - there was no way we could make it sound good through PA (headphones were ok at best). The expression pedal feels weird as well, but not as in bad-quality-weird, just weird on a personal-opinion-level.
TL;DR
The effects are nice, there's little to no lag, it handles itself well, but for the love of God are the amps and especially the factory cabs bad.
Sounds good at best through headphones and bad through mixer and PA, both with custom IR and factory cabs. Build quality is good and feels sturdy. It has no on/off button, which is very annoying and confusing.