I have not tried the Carvin, but I have owned the GK MB200 for awhile, now, and I have pretty much relegated it to a headphone/practise amp for home use only. It saved my butt once on a gig, but I was'nt really concerned about how it sounded then; I just wanted to get through the gig. Subsequently, after trying it on some gigs, I could not get comfortable with the tone I was getting, and found myself constantly fiddling with the controls. I even tried it with a 1500 watt power amp, and it definitely can push a power amp , but, I just could'nt dial in a tone I liked. It serves excellently as a small headphone amp to learn new tunes hooked up to my computers, or just a stay at home, noodling around amp. Definitely the form factor is excellent; fits into any gig bag, but you get the GK MB tone, for better or for worse. I bought a Carvin BX 1500 in the meantime, and instantly fell in love with it, especially the EQ and compressor. If the 250 is anything like it, I would jump on it as a backup head. Although, I don't see the advantage over a BX500, which has the excellent ( imho ) graphic EQ, and twice the wattage. I was toying with the idea of actually getting a BX 500 to rack with the BX1500, in case either one went down, I would'nt have to change anything but a speaker cable. Still, that little BX 250 is tempting.