Extra barrel for Glock 32 -- factory or aftermarket?

[Halo]

I just got a lightly used Glock 32 and I want to get a .40 barrel so I have the option of shooting either round. Should I just get a factory G23 barrel, or do you recommend one of the aftermarket barrels instead (and why)?

I really like this pistol so far! It seems to fit my hand a little better than my Glock 17. The snappy 357 SIG is fun to shoot!