Don't have one myself, but I've been reading and thinking about accurizing my Mini for some time. The consensus is that a strut dramatically reduces inaccuracy caused by barrel harmonics when installed on the pre-tapered Mini barrels. I haven't read anything conclusive about accuracy improvements due to struts on Minis with the newer tapered barrel. On those, the strut just makes it look cool. Nothing wrong with that.
And of course the strut does nothing to improve the shooter, unless you count the impact of thinking your gun looks cooler. Personally, I hope it does.