I have the adjustable Ryobi and I love it.
We'll worth the money.
When I do heat shrink tubing on my assist setups dialing down the temps is great. Them I can turn it up for jigs.
I keep it lower for smaller jigs and higher for bigger jigs.
Smaller ones can melt if I'm not careful on the heat but turning the temp down helps a lot and I don't have to be so careful.
A regular gun works fine but I like the one I have its more versatile for me and if I had to do it over I'd still spend the extra for the adjustable Ryobi.