I am using a 200watt won Pro-Heat Titanium heater and I absolutely love mine.
Pros:
1 won't break like glass and fry your tank
2 has a remote temp control so you can adjust externaly
3 heats up a lot faster than glass and is designed so it can run all the time
4 very accurate setting (mine only drifts 2 degrees max all year)
cons:
titanium heaters are supposed to be placed verticaly only. horizontal will cause problems. Mainly a problem for guys wanting to place a their heaters in a sump.
I have a 300W titanium heater in my 360 and it has worked very well. I have it horizontal in my sump (had never heard about keeping it vertical) for 8 months and I have not experienced any problems whatsoever.
I have 2 of the 250 watters, and love them, on sale at www.oceanencounter.com I spoke to someone over at Won Bros. and the verticle thing is a misprint they can be mounted in any direction with no problems. Both of mine are mounted horizontal!!
I run one in my 125. It is the best thing since sliced bread. You don't have to worry about breaking the glass. You do need to place the tape on the dial, but that is not too bad. Look on Ebay there is a guy that sells them like crazy.