i've been playing with my Aguilar DB 659 for a few months, i used to use an SWR IOD,...moved on to teh Ampeg SVP-Pro...didnt like that so 3 weeks later got the Aguilar DB 659, i love this thing!
The SWR did the lean and mean thing really well, and had really nice overdrive options, but for meaty fingerstyle for old school rock, it didnt satisfy me, great for slap and other types of fingerstyle music though. Wanted a meatier sound and of course I tried teh Ampeg SVP-Pro. It was really thick tubey, but i felt it covered up my bass too much...
the DB 659 is great. It lets through that "thwump" of you really dig in for that sort of 'punch'/percussive hit (like a thumb slap), has a really nice full fingerstyle tone that i dont even need to EQ, but is there if i need it. Has a bright switch if you need that high end tweaking, and really nice effects loop options in a 6 lb 1 space package.
i highly recommend it.
only reservation is that the EQ is tube driven (i think?) so its not hugely powerful like lets say, Eden's preamp, but it does more than enough for me, very smooth even when you dime a knob, doesnt get raspy or harsh with my setup.