It looked like Cell essentially reached SS2 when he unlocked his Super-Perfect form(his aura was literally identical to SS2 Gohan's...complete with the trademark 'lightning bolts'.) If so, then SPC would be superior to SS2 Gohan.
FP Perfect Cell > SS1 Gohan. SS2 is 2x SS1, which would therefore make SPC > SS2 Gohan, if indeed his Super-Perfect form was equivalent to SS2.
Now, if Gohan is able to fully dig deep, like he did during their final beam-struggle, then he could win. Back in Z, Gohan's power reserves couldn't be touched.
So, Galan, you're saying that Gohan won only because Goku kept pushing him? And because of the distraction Vegata (canon), Vegeta & co (anime) provided?
What about his broken arm and supposed 50% power loss?
I realize Gohan was no fighter, but he was no slouch in the power department -- and who knows how it would've gone if not for his arm.
Gohan's power was always tied to his confidence though. Radditz saga established that. And Saiyan and Freeza saga's showed he probably could have seriously contended with Nappa and form 2 and 3 Freeza.
As Stilt said, he was in bad shape and feeling guilt over inadvertently causing his fathers death. He essentially hit rock bottom, confidence wise.