I've got a Lone Wolf 5.15" barrel for my M20. It sticks out a bit but not enough to matter for carry, but it does give that extra little bit to velocity.
You can purchase a 5" or 6" slide from LWD for $260 stripped.
You can get a 5.15" or 6.02"/6.52" barrel from LWD for $124 everyday including Christmas.
Only you can decide it it's worth it to go "long slide" but for field use in a 10mm it's hard to beat the added velocity.
I'm thinking about keeping my stock length slide, putting in the 6.52" threaded barrel and machining a custom "slide profile" barrel weight that threads onto the barrel and blends it all to the slide. The reason is because the added mass would delay slide unlocking, but once open the reciprocating mass would be the same as stock. Long-slide pistols can get a little sluggish on cycling because of a greater total cycling mass.