Here's a pic of a very basic Tac squad of Blood Ravens. 5 men, with a Bolt Pistol/Chainsword sergeant. The Sarge is the only one built from actual tactical squad bits. The squad members are all made from the three-piece "Battle for Macragge" starter sprues. I had a whole BUNCH of those guys lying around.
I never really saw any of those starter-marines painted really well. Those are among the first minis that people ever paint up, so naturally we tend to see a lot of those starter marines painted like butt (to be quite frank about it). So I thought it would be a fun exercise to give them a decent paint job.
They look pretty dang good, if I do say so myself. Also, I'm not cool enough to print out my own decals, so the emblems on the shoulder guards are all done freehand :-P
In terms of using these guys in a game, I made the basing match my existing Black Templar marines, and my planned Imperial Fists marines. This way, I could play my Templars, Fists, and Blood Ravens as a Black Templar army, with allied Codex Marines.