Character customization and amount of content was far superior in SR2. SR3 is pretty much all tutorial until the last 15 missions or so. Also the story (not really a highpoint of the series though), characters and gangs are inferior to the previous Saints Rows. SR3 may have the edge in content one day when you take into account the billion DLCs they have planned.
I also didn't care for the character upgrade system they used in the game. Maybe it's just me but I loved unlocking things as a reward for doing activities and missions. And the rewards could mostly be unlocked in whatever order you chose. Maybe some people didn't like dual wielding automatic pistols with infinite ammo early on in SR2, but I sure as hell did.
SR3 does do some things better than the previous games. But taken as a whole, it's an inferior sequel.
Just when I was about to run out and snag SR3, I'm suddenly left wondering if I should wait for a GoTY edition. DLC packs? :/
As someone that -never- enjoyed my multiple attempts at playing SR1, I'm still altogether hesitant with giving the series another shot. The insanity sounds great, but given how quickly 'god' mode is activated in SR3 via skill perks(according to Bombcast)...I'm just not sure if there is even a 'game' to enjoy? Or just a wacky funhouse full of stupid to just laugh alongside with.