The advantage of the dark angels chapter is you get a LOT of mileage out of specialist sprue,  The problem with them is they are currently once of the oldest codex s and it was written for prior to the new codex space marines, which gave a lot of points reduction.  They are farther down the codex creep scale. 

On the table top you will either do really well or really badly with the death wing or raven wing companies.  My Dark Angels do not see a whole lot of the table top,  but then again neither do my Salamanders or my Imperial Guard or Tau. 

On the other hand Codex Blood cheese is one of the newer codex and it is the "pet" army of the studio, a slew of beardy characters.  There lots of specialist kits and sprues that are out now, such as the furioso Dreadnought, baal predator and the new Storm raven gun ship was released last week in a black box.  The Blood angles Terminators that are in the new copy of space hulk board game are stunning if you can get your hands on them. You can get more information on these at http://www.bolterandchainsword.com/  which is in my opinion one of the best space marine boards on the net.