Gohan likely wins, but it's not a stomp by any stretch, imo.
Daizenshuu #2 implied that Goten was on par with Gohan at the start of the Boo saga. That, coupled with the boys' respective showings, make me believe they were really close to the adults in power(closer than most think.) That said, Trunks+Goten could very well be more powerful than Gohan. However, even though Gohan had become lax since the Cell saga, he would still hold the decisive edge where skill is concerned. That's why he wins.