This was a Valentine's Day episode, and when you consider a program which has a character like Barney Stinson on it, Valentine's SDya is certainly an exciting prospect!
The term'Desperation Day' referred to the day befroe Valentine's Day - I enjoyed Barney's ancient Roman explanation on what Desperation Day is, and that was very funny!
However, the episode went downhill from that point forth. It was not very interesting as the episode eventuated, and I didn't enjoy the whole scene with Robin and her female freinds. It was not enjoyable at all.
As fo r Marshall, I hopef that he won't disapper again, because it wasn't interesting with a character in another city. Glad to have everyone back in New York City.