I'm not sure if the different widths have an easier time getting hot, but I can't get the temps in my tub high enough just using 4" flexwatt. I can set my helix to 100 and the probe right on the tape only gets to 94. The temps inside the tubs only get to 84.

I've ordered some 11" stuff so I can try it out.

I currently have some zoo med UTH's under my tubs and without hooking up the tstat they get the area above them to about 94. If I hook up the tstat I can't get it that hot. Maybe there is something wrong with my helix. I should note that I couldn't get it hot enough using a ranco tstat either.

Heating is SOO much fun!