As a member of a team that often goes overtime, sometimes well over, we do the jam just to have fun and make a game we are proud of. So if our game just doesn't really work when we hit 3 hours, we will go overtime to get everything done. Usually what happens with us is it takes multiple (2-3) hours to just finish things up, or sometimes we might just decide we want to go overtime to do our idea justice.
I've done probably 20 trijams at this point, and especially with my solo games i find the 3 hours not leaving me enough time to make something that feels fleshed out. In terms of getting recognition, actually a large portion really just comes down to a good thumbnail, and commenting on other people's submissions.