Personally, unless you go completely shooty, footslogging CSM is hard to do. You can do it with large squads with Icons of Tzeentch (against plasma, battlecannons, etc) or Nurgle (yay large T5 unit), or simply spamming CSM with Icon of Chaos Glory, but it's still hard to play. Fully mechanized is also tricky, but I think if you know how to use armor effectively it's definitely stronger - the key here is learning how to use armor and Rhinos well. Half-mech is reasonable, and decent to play, but doesn't have the full strengths of either of the full-style lists. Doesn't have the full weaknesses either, though.
Unfortunately, since the FW Drop Pods are listed as "Flyers" and appear only in Imperial Armor, most tournaments won't let you play them. They're also overpriced compared to Imperial drop pods. However, I've really wanted to make a list using them - Chaos Dreads dropping close, Thousand Sons or Plague Marines appearing close to their targets without taking fire on the way - yeah!