Ok, so I just picked up a GK backline 600 and a GK Backline 210... I got it so I can do the dual amp thingy.. one for clean and one for effects. This amp is my effected signal. My 'clean' signal is an Ampeg SVT3-Pro into a Aguilar 1x15. Gotta say up front that the GK kicks... Total price at GC was around $500. The tonality isn't as good as my Ampeg SVT and Aggie cab, but it's a pretty nice l'il rig. I have the 8 ohm cab, so it's 200 watts.. and it's a loud 200 watts. This amp has a distortion channel, and it's actually not too shabby... I may actually use it, too, when I get an external footswitch. It'll be a nice addition to my muff and my hot tubes. The response is great, even on a 5-string. It's nice and punchy, too. The cab doesn't weigh a ton, and it's got nice handles. The head weighs about 20 lbs. My only beef is that the EFX loop, line out, tuner out, and footswitch are on the front. Not my ideal set-up, but not a biggie. The speaker jacks on both are 1/4" only, and the cab doesn't have a high-pass filter control. The head has 2 speaker outputs, however the cab has only one I/O. Also, while the amp IS rack-mountable, the rack ears are sold separately. Still, If you are looking for a good back-up amp, or a good gigging amp for less than $600, this is the rig I'd look at.