i have the stock JBL system and it sounds great. maybe not if you're looking to make your ears bleed, but... even with the JBL i have considered replacing the stock sub/amp and front door speakers, they seem to have the most trouble when you really want to turn it up.
I have the 4400bh and i had to trim around the entire inside of the frame. i also had to square out the rounded corners. works pretty good now. i used a box cutter razor type blade and shaved off a thin layer at a time, it still looks clean.
I actually picked one up a couple weeks ago as well. Its AWESOME! There's not much about it that i don't like. Be warned though, the Metra 8210 install kit (if thats the one you get) doesn't work so well without a fight!
