The biggest criticism I've seen regarding Bugera amps is that they have somehow successfully cloned a bunch of amps both tone-wise and cosmetically without any trademark infringement violations being brought against them.
I've seen a number of reviews on the Bugera amps on a number of different forums and the vast majority of them are very favorable. Tone wise, they get some pretty good reviews and I haven't read anything about reliability issues thus far.
Most of the amps they build though are 120 watts which to me is overkill.
Guitars: 2003 and 2004 American series strats, Squier Classic Vibe 50's Strat, Squier Deluxe Strat.
Amps: Line 6 Spider IV 120, Vox AD50VT 212, and Peavey Transtube Bandit 112.
Pedals: Digitech Bad Monkey.