I have both.
Model 17 8-3/8" and a 4" Model 18.
Personally, I prefer the 18 for anything except rimfire silhouette shooting at 100 meters, which is what I purchased the 17 for.
The 18 just handles and feels "right" to me. the Ahrends stocks help a lot, too. I like them enough that I'm gradually switching all my revolvers over to them.
I can also say the same for my Model 14/15 pair.