I have both of the mods you mention. For the size, the SL5i is hard to beat. It’s also lighter and adds less length to the rifle compared to the evo. Both mods offer great sound reduction. I’ve had comments on both mods from guides and friends as to how effective they are.
If it’s a stalking rifle, personally I’d go for the SL5i for the reasons above. Plus I prefer an all stainless mod.
Ultimately, you can’t go wrong with either.