I prefer NL these days. I have 10s of thousands of limit games under my belt, but I have come to the conclusion I just can't take the huge amount of variance you can encounter in limit. In NL at least you can modify your betting patterns to try and combat a bad run. In limit the bad runs can be absolutely brutal and there is little you can do about it except watch as hand after hand after hand is beaten by inferior holdings.
There is no doubt however that NL is a world apart from limit and requires a much larger knowledge base. It is also much more demanding on your attention. Where limit can get almost mechanical, NL is anything but. Dividends will be paid for every hand you pay close attention to even when you are not in the hand, making mult tabling difficult, unless you don't mind a marked reduction in the quality of your play.
One last thing, if you play limit do yourself a favor and don't use a cordless mouse. They are way too handy when you lose the 15th str8 hand to a draw out
