The wife and I went to see this Friday night. We went in wanting a Cheesey B-Movie-fest with added 3D, and it's exactly what we got. The FX were so-so in some areas, and really quite good in others. Same with the 3D, like most 3D films your mileage will vary depending on the cinema and the setup. I was surprisingly impressed with the 3D conversion. I think it tells that this film, whilst shot in 2D, was intended for 3D from the start rather than 'Clash of the Titans' where it was done as an after-thought.
It will also probably be the only time I ever see a detached *censored for spoiler* floating around in 3D.
This, like Snakes on a Plane, is a film that can make or break on the audience you see it with. The theater was pretty damned full given it was an 'early' showing on a Friday, and the audience was surprisingly female-heavy. It just made the yelps and occasional screams all the louder. There were at least 2 rounds of applause.
Christopher Lloyd was slipping right back into Doc Brown mode, and Dreyfuss was TOTALLY playing an older, more inebriated version of Hooper. I don't care what the credits say.