That person trying to rip off Renn's head in silhouette at the end made me think this was going to have some wacky gruesome ending like those Nick and Renn CHUD videos. Also, I don't think "Eternal Sunshine of the Spotless Mind" is in the same league as "Annie Hall", but I understand why they were brought up as reference points.
"Eternal Sunshine of the Spotless Mind" does pack an emotional punch, but I thought it just had a very, very obvious message and didn't tell me anything I didn't already know. "Annie Hall" on the other hand, was chock full of illuminating insights into relationships and witty dialog. Suffice to say there hasn't been a romantic movie with as much emotional impact or insight as either of those in a long time.
