As far as I can remember, Jamie, there have been a few cases of flexwatt doing quite the melt job on tubs. T-stat malfunction? flexwatt malfunction? not wired properly? I dunno. Based on my limited experience, the heat rope has been easier to deal with and control over Flexwatt.
I've always felt more comfortable with the heat cable on my AP racks than flexwatt. I've heard many stories about flexwatt overheating, shorting out, causing fires, etc. Never heard anything like that about heat cable.
Lucifer Sam, Siam cat...
Always sitting by your side,
Always by your side...
That cat's something I can't explain...