Frankly, I like live play better. I don't claim to have any polished ability to read opponents, but I find that I play tighter, better poker live than online. I also like the more relaxed atmosphere, talking with those beside me, and the waitresses bringing me drinks! I think live play is just more fun. More importantly, I think there is more loose money in live play than in online play...lost of retired folks wanting a little action, folks who would never play online and play very loose and passive.
Let me illustrate what I talked about, above. I just got back from my local casino. This is my 5th trip this winter. On the first trip I played $1/$2 No Limit Hold'em. I bought a Coke just before arriving at the casino and left it in my truck. 2 hours and $200 later, I was on my way home and the Coke hadn't even had time to get warm! The No Limit games are populated with decent to very good players who will put you to the test for all your chips in a heartbeat. Before the second trip, I decided that a change of game plan was in order. I played $2/$4 Limit for 7 hours on $100 and ended up winning $20. The 3rd trip, I won $130. On the 4th trip, $70 (after being up over $150), and today I won $190.
Again, I make no claim to be a great player. But, the trick to beating these games is tight, solid poker. Believe me, you will be the only tight player at these tables....75% of the time there will be 6-9 players seeing the flop. Almost no one folds, so don't even bother raising until you think you have the nuts or near nuts...then punish them. Beware...Granny will play any two cards to the river and will occasionally hit her runner, runner straight to beat the set that you hit on the flop (happened twice to me today). But, this loose, reckless play is what makes you money over the course of a 6-8 hour session. Tight play means you won't win as many pots as those playing loose. But, you will save a ton of chips by not chasing rainbows and the pots that you do win will be very healthy ones.
In my experience with live play at lower money levels, No Limit is dominated by players powered by testosterone. If you want to "prove" yourself, play No Limit. If you want to make money, play Limit. I have found the 2 cent/4 cent and 5 cent/10cent Limit tables online MUCH tougher to beat than the $2/$4 Limit tables at my local casino.