Ali1 benched the new bxi2608's and his numbers were not too bad. This year's Hifonics amps look like they are underrated so you might get more out of that 1608, but I could be wrong.
I cant help with the 08 model,but my friend uses a 1605 on a ma audio 18 and does just fine. I have another friend with a bxi 1206 model on two jlw6 12s and it sound pretty nice. Bottom line, they do well for little coin.