I loved this episode. The main storyline with Chuck and the team was really well-developed, while we got to see some of Chuck and Morgan's adorable little bromance again. There was some great action - it had the typical physically-impossible-and-vaguely-ridiculous-but-totally-awesome-to-watch Chuck action bit which we seem to be seeing many of, which is great.
Best bits: Vivian (I know her as Bela Talbot from Supernatural, so it was great to see her back on TV), the entire 7 minutes before the title sequence (the Valentine's day bit - it made me cry laughing), and the fact that some of it was set in England (that's just me I'm afraid, being a Londoner. I love seeing other countries' stereotypes/views of us, and Chuck's blatantly fake accent was genius).
Worst bits: Can't really think of anything, but I guess that fact that no music was featured that I wanted to buy for once. Ah well, my iTunes bill will be smaller because of it.
If you haven't already, go watch this episode. It's probably one of the season's best, in a subtle way. It's the usual Chuck: hilarious, sad and happy all at once. You won't be disappointed. There are also some serious cliffhangers at the end which will keep your brain buzzing 'till next week. :)