I just swapped in a Arc Audio 4150 CXLR for the JL 300/2 that was running my Dynaudio System 340's up front, and WOW. The JL was doing ~150-175 per channel, and the arc is bridged to 320 per channel. The Dynaudio's LOVE that extra power. It gets LOUD while staying super crisp. It's has to be close to twice as loud now, before the tweeters start sounding a little harsh. Oh, in back I'm running a 10W7 slot ported with a 500/1 on it, and it's all in a 2003 Camry.
I know you're not supposed to be able to tell a difference between amps, and the difference I hear is most definitely the extra power. BUT, Arc sure seems to put out a nice product!