I don't think there is a right or wrong answer, just depends what works for you. That being said, it can be expensive to experiment!
I started with variables on my revolvers, and now am running Luepold fixed 2x on both of them and am liking it a lot. I can see where a 4x could be a better choice in certain situations, but for a lot of my hunting situations the 2x has been nice. Maybe I need to get another gun to put a 4x on!
I like the compact size and light weight of the fixed scopes on the wheelguns, I find that in the "moment" I am not distracted by dials to turn the power up for a better picture, but instead focused on the crosshair and where it needs to go. I think there is something to be said for the durability of fixed powers also. I have had my share of troubles with variables(they were both Burris) and was looking for a tried and true answer that I know can hold up to recoil and be dependable.
There are many very experienced folks on here that have a ton of knowledge to share, and many of them may have differing opinions than mine. that's OK, I may get there some day
"If you are going to go through all the trouble to put a hole in something, why not make it a big one?"