Flexwatt?

Alright, I'm upgrading to a bigger tub soon because Kaa is getting too big for his 15qt quickly! I'm going to be upgrading to a 25qt, and I know Flexwatt is a much more affordable and more reliable heat source. Are there any complications with it that I should know of as a first time Flexwatt user? And where/what should I get? What kind of it should I purchase? (I believe there are different sizes.)

Thanks!

Yes Flexwatt is cheap, I have never found it more or less reliable than anything else. It does hold a large downside. It in the event of a tstat failure gets seriously hot. There are a handful of UTH that under the same event do not get seriously hot. Many of this type stay below 100ºF in the event of a failure.

Any examples? I just need to heat my BP's new enclosure and I did not like my ZooMed. It doesn't stick to the bottom of the bin and falls if I tape it.

Ultratherm would be my first choice but intellitemp, Kane, exo terra rainforest (not great UTH these) I understand that the zilla UTH as well I am not 100% on those.