RTD's record on season finales living up to the build wasn't that great. Episode 12 was almost always a lot better (personally a lot better, though for season one that's not because of anything wrong with Parting of the Ways).
I agree that it's all how each individual views things. I'm just not that overly keen on Moffat's writing, at time the show comes across as a convoluted, timey-whimey mess that shows no indication that the Moff really has a plan.
Still, I'll remain open-minded on this ep until I see it, mainly because I really want it to be good. But I also agree with one of the above posters that there's an awful lot to cram into a single episode and try to resolve.
Frankly, I think the problem is that he has too many plans.
He starts the season with a clever, left-field, well thought out idea. But halfway through production he wakes up in the night with a new idea, and adds it in, and in the process the original idea gets over-complicated and lost, and the season finale disappoints.