I prefer U-40. This is the kind you don’t mix just put it on straight from the bottle. I like it for three reasons:
I can not mix anything right and probably mess up any other finish and do not want the mess of cleaning it up and starting it over.
I have been building spinning rods for about 30 years now and that was the first finish I used and just stuck with it.
When I build a rod I want something different then the factory rods. The biggest thing is the wraps. With the U-40 you don’t have that factory look on the wraps with the big build up of finish. this is just my personal opinion and nothing more. With the U-40 you can see every wrap of thread which I think is kinda neat. It seals just the same as any finish just not as thick.