I have Focals in my car. I started with coaxes from the Access line, changed to 2-ways from the polyglass line, and currently run 2-ways utopias. I would say they are all similar to the axiom sound. The crossovers (on the ones I have) are adjustable and I have the tweeters dialed back quite a bit. I will say if I had it to do again I'd stick with the polyglass, the utopias aren't enough better to justify the price in my loud-ass car.
I listened to diamond "hex"s in '03 and they sounded very similar to the focals. When auditioning, my impression was that the access line was a significant jump in SQ. over the slightly cheaper more mainstream brands. I would recomend a healthy amp as the next upgrade after speakers. I would also suggest considering the "front stage" approach- put your money into 2 great speakers in the front and forget the back ones. The catch is you need that heathy amp to really pull it off well.
