I play both, live and online, less live lately, but getting back to it. I have more experience playing live cash games than online, and I find them to be very different in how they play ... and where I feel very good about live cash games, I am really just now starting to learn online cash games. So there is a lot of studying going on.
As far as tournament play, I prefer online, to brick and mortar, simply for the convenience of being at home and comfortable, however I am dressed or feel. Another thing I would point out is the time involved, my last online tournament was a few days ago and it took 5 hours to wind down and bust just outside the final table with 560 runners, and 15 minute blinds ?? IIRC ... a similar live tournament would have taken days possibly, depending upon the blinds of course
...
Online I started with tournaments as freerolls, like many here it was a road to having cash without making a deposit .. and so far it has worked fairly well. I also think it is better to start, at the bottom of the pay scale so to speak ... so freerolls filled that role ..
I have to say I do prefer the excitement level and unknowns of tournament play, there is nothing like outlasting several hundred to come close to a win or actually take it, or to come back from the dead to do well : )
Cash games for me are rote play and really just to make money at least at the levels I am playing online so far, I am sure in time and provided I am able to move up the stakes, the challenge will increase.