I tried to get into Deadwood but couldn't. It is way too much work to understand what they are saying (at least for me). Where I'm pretty much on the same sophmoric level of all the guys on Entourage.
Deadwood does take some getting used to. Reading the episode guides after watching a show can reinforce certain plot lines that may have been hazy after the viewing.
Every third word is the F-bomb, so you only have to catch 66% of the dialogue to know what they are saying.