I use them a bit but mostly as light boat reels, I prefer a conventional fixed spool reel for spinning and lures, especially light lure (though this could just be me).
They are prone to tangles if you don't set them up properly. Firstly you have to set the brakes for the lure - and do this each time you change to a heavier or lighter lure -
http://www.youtube.com/watch?v=6DCXdzRak5Y
If the brakes are too tight you won't be able to cast any distance, but if it's too loose the spool will keep spinning as the lure slows down in the air, giving you an over run, if it tangles the line can snap and you lose your lure.
Also when casting keep your thumb lightly on the spool. As the lure is about to hit the water tighten down on the spool a bit and slow it - the line is no longer being pulled out by the lure but the spool is still flying, if you don't do this you will be guaranteed a mess.
The third place you will end up with a tangle, and it's the worst one, is if you release too late in your cast and the lure hits the water too fast for you to brake the spool. You will end up with the mother and father of all birds nests and it can end your day.
When it happens you will need this tube here
http://www.youtube.com/watch?v=TDI5kwR5zjc
I've had my share of tangles on these reels and this is how I free them, I've only had to cut the line once. Like I said I prefer a fixed spool reel for spinning and lures, I find baitcasters don't work as well with very light lures, or with heavy line.
There is plenty more on youTube about them so have a look, and enjoy!
