There are just some sections in which the volume of enemies may be an issue imo. I think I'm just so used to twitching around on my keyboard that I can't imagine it on a pad. But I'm very interested to see what happens with it.
Is HLDM2 included on 360?
You have to remember the Xbox 1 ran Half Life 2 just fine, and that's far more intensive than Episode 1. The Source games will be a cakewalk for the 360.