Raimi's quirkiness is not for everyone.
I personally felt the film lacked energy for the most part, except in those scenes when Parker is rocking out the 70s pelvic thrusts and showin' up folks. The dialogue he has with Ursula (cake girl!) while he's on the phone with Doc Connors was hilarious. Seemed like when Sam and Tobey were having the most fun.
But for the most part, the entire cast seemed like they were going through the motions. The energy from the first two dissipated as soon as Spidey separated from the symbiote, and there wasn't a ton of momentum in the film prior to that even.
Reading a few of the geek boards, it's also no surprise that the third act possibly has the most material cut from it. There are folks that are speculating that good 30 minutes or more has been cut from the film, most of it involving the Sandman's family, Eddie Brock before his change and the resolution at the end.
I can see why folks would be upset by Sam cutting those scenes instead of his quirky ones, but I felt he made the right decision - if he had to keep something, those few shining moments had to be it.