Thinking about grabbing RDR since I had the base game for 360 but never finished it due to RROD.
How long is the Undead expansion for RDR and is anyone still playing it online? Also, does the Undead tie itself in with the main story or is it like GTA IV where you launch it separately from within the base game. Personally I like the separation they did with GTA.
Undead Nightmare was fairly short and got repetitive really fast (clear town, clear graveyard, repeat), but it was still fun.
It's no where near as good as the 2 GTA IV expansions though.
I did get frustrated when the main story wouldn't advance until I finished a side mission that I had attempted and failed once (glitch maybe?).
I never touched the online portion, so I have no idea how active it was/is.
I can't comment on the separate launcher, since I have a the Undead Nightmare collection on disc.
I paid $15 for the stand alone Undead Nighmare collection and thought it was a good purchase (I loved the main RDR game/story).