Its clear to me, that the main problem of JLA is the pacing. Really, other than that, the book is solid (I refuse to accept the whole Hal/Red Arrow thing as an actual problem) but its funny, a lot of people had the same complaint about Identity Crisis when it came out. JSA, was just gangbusters, but its really at its core pretty different situation, the JSA has its mainstays and the whole recruiting aspect was handled better, but because the circumstances are present to make the transition better. You look at JLA, you have a group of different people coming together that have really no relation with each other. Its a lot like the original Avengers. You look at the JLA mainstays and its clear that the circumstance IC and OYL put them in, its impossible for them to be in with each other.
Martian Manhunter is all emo and human hating, Bart is the Flash, please, he is not JLA material (I think he'd be interesting as a guest star on JSA), Aquaman has a squid face and Aqua Newb is busy with other stuff apparently, Ollie is Mayor of Star City, thats a 24/7 job already.