So, Ive been wanting an Aguilar DB750 for quite some time to use for both backline for festivals I book and as my gigging rig. I went to pull the trigger on one here yesterday but didnt have the funds (LONG story). Im on here a lot reading about amps, and a solid, less expensive although top-shelf -- alternative seems to be a Thunderfunk. Tomorrow Im going to a fellow Detroiters crib to check out a 550-B that hes selling for what seems to be a very fair price with a road case. (Hes actually got two of these and is looking to thin the herd.) I play in a jump blues band, both upright and a P (single coil), and I like a lot of basic thump. Often I jam a piece of foam under the flatwounds to enhance that sound. I like the sound of Keith Ferguson (T-Birds). Currently, I use an old GK400RB through an LDS 1x15 (8 ohm). Its a cool sound, but sometimes Im maxing it out and getting more dirt than I prefer. I want more headroom, which Im hoping the Thunderfunk will do. I dont do any slapping on EB, but some on UB for rockabilly-type stuff. I dont play modern by any means. I just want to feel the notes and that whack in the middle of my chest. From what Ive read, the DB750 will deliver that in spades, but how about the 550-B? Id like to pick up another 8-ohm 15 down the road for the festivals. I see lots of different posts about gold chips and upgrades to Thunderfunk amps. Beyond if the amp sounds good with my P and cabinet, are there any other things I should be looking for on a 550-B to determine if its a solid investment at $700? Long-winded, I know.