In the subject guns & calibers, I have/had a G17gens3&4; G34gen3; G22gens2,3,4; G35gen3; and a G31gen3.
I don't care for versatility and prefer choosing, shooting, or carrying the right gun for the purpose at hand.
I'd rather have a complete gun ready-to-go than to have barrels, magazines, ejectors, and sights for one caliber which all need to be installed along with bringing the correct ammo to the range or carried. Reliability can vary with aftermarket barrels or a given Glock could be completely reliable with a conversion barrel. Only spending the money and trying it will determine that reliability. Entire slide assemblies can also be bought/put together for the G22/G35 guns, although Glock doesn't sell just a slide directly to customer.
The longer G34/G35 wasn't too much of a bother compared to the G17/G22 for carrying, usually inside the waistband. The slide is 1" longer and you may want something shorter. I do usually carry my G19gen3 most of the time.
I don't worry about the open slide cut of the G34/G35. In an urban setting or at the range, I wasn't using these guns in dirt, sand, or gravel to any extent. I also carry a backup gun, however. For my LEO work, I'm now issued and must carry the G17gen4. If carrying my G34gen3, it's off duty or I'm just enjoying shooting it at the range.
My department switched from .40 to 9mm and I sold off my G22 and G35 guns for lack of use or interest. They were just taking up space in my safe. I still have a G23gen3 as my last .40 gun should I want to shoot that caliber.
A note on the G34/G35. Glock typically has two versions which may be stocked by a dealer. The standard commercial version will have a "MINUS" or 4.5 pound connector and an adjustable rear sight.
A "Blue Label" version will have a 5.5 pound connector and fixed sights. That's the way it was with the G35gen3. I suspect it'll be the same with a Gen4 version. My dealer's website indicates the G35gen4 "Blue Label" has an adjustable rear sight, but the website could be in error regarding that rear sight.