I have owned and shot 10 mm for 25 years. Used to have a first run Colt Delta Elite. I recently (the last 6 months) discovered .38 Super. It didn't take long to fall in love with the round. I think both have their place in any collection.
The .38 Super has a lot of the attributes of 10mm (flat shooting, accurate), but with less recoil. As I age, arthritis and winter some times make shooting 10mm a bit painful. I can shoot .38 Super all day long. I still carry .45 ACP as well as 10mm, but have been carrying commanders in .38 Super more and more.
As others have stated reloading is probably the way to go, with both rounds. That will be my retirement endeavor, reloading and shooting a lot.