Hifonics class D amplifiers worth there money..?

guy that i buy my equipment from says there really good but hes a salesmen lol

never seen them run maybe someone on here has seen these run or had one once before and let me know some info.. also i was wondering how Hifonics is compaired to JBL amps cuz if JBL amplifiers are worth the money then ill buy the dudes amp. in the for sale forum...