I've used miles of the stuff in industrial applications.
The Teflon handles higher temps but is much less bend radius friendly. Once you kink it, it gets a memory too - i.e. if you over bend it towards an old kink it wants to kink again on the old fold.
Rubber hose is much better in constant back and forth motion situations.
Teflon blows away the rubber hose on chemical resistance.
Teflon tends to let go of the barb more often than the rubber hose in my experiences.
Carb so low psi. And mostly racing fuel sometimes 93.
I heard the newer fuel that contains ethanol doesn't get along well with rubber very well but I still see people using plain Jane rubber fuel line from things like the mechanical fuel pump to the carb.
As for heat, anything that will pass by the exhaust will have the heat shield covers on them like you see people use on spark plug wires next to the headers. Added security.
teflon doesn't have the fuel vapor smell like the rubber kind does.
Shouldn't ever have to replace teflon, rubber gets sorta old and hard over time with ethanol content in fuel. However I believe most mfgs have gone to ethanol resistant linings on the rubber stuff too.
if you buy rubber, buy fittings and hose from same mfg, and the little bit more expensive stuff is a lot nicer to work with.
Alright well I bought the rubber braided stuff off eBay from Summit. -8 and -6. I'm going cheap on the fittings tho, I had to skimp out somewhere. Ends will pretty much look like this. Not the best but it should work. Every sales rep I asked said it would be fine since it's low pressure, I asked before I ordered to and they even told me that the fitting would be tight and I'd have to use some lube to get those barb fittings on.