I bought this amp a few months back when I got into gigging at the local bar venues. Many of the people i talked to said for a bassist you really need around 300 watts to get good sound. I took a chance and got this instead. I'm guessing those people had not listened to this particular amp before. The rest of my band is quite fond of cranking it up, and their rigs aren't exactly modest. That being said, their number one complaint is that there's too much bass in the mix. I am constantly amazed at how much power this thing has. not just in sheer volume, but actual POWER. Put this thing anywhere but on a concrete foundation and it'll shake the floor beneath you even at modest volumes.
That being said, it isn't without drawbacks. This is an awfully awkward piece of equipment. Moving this thing from gig to gig isn't really any more convenient than moving a 4x10 cab. They've made an effort to ease the burden, but it's still a 55 pound cube about the width of a doorway. Also, the single 15 while powerful does muddy your sound a bit. It's not enough to ruin the experience but if you want a lot of mid range definition you may want to aim for something different.
Overall I'd say this is a solid piece of equipment and good value for money. It's built to be sturdy and makes a good sound. You also get a fair bit of little extras in this model like XLR direct out, 4 band EQ, shaping buttons, and overdrive (which doesn't have enough kick for me, but a decent pedal can fix that). If you're looking for an efficient all-in-one option for gigs and practices I'd definitely recommend this amp.