I've been using RDS on handgun long before they became a thing and this is what I've learned;

Don't think a RDS is a fix-all for crappy shooting. It isn't. They still require a solid draw-to-grip-to shooting stance, good trigger control. and decent recoil management (probably better recoil management than "standard" sights).

There is a transition period when changing-over to a RDS and a transition period to revert back to standard sights if are so inclined. It's all about conditioning yourself and once you are conditioned to use the RDS, reverting back isn't as easy as removing it, which leads to...

Once you decide to go/stay with a RDS on a serious-use handgun, it is a smart move to assure ALL of your serious use handguns have RDS on them.

It isn't as hard to condition yourself to use a RDS handgun, but it isn't easy. Lots, and lots, and lots empty-gun presentations from the holster will build your engagement speed quickly, then you'll need some dedicated range-time to work-out the live-fire quirks. The biggest one being that your recoil control needs to return the RDS handgun almost right back to the exact spot it was fired from. If it doesn't, you'll find yourself hunting for the dot for longer than you would normally had for the front sight. There are many more visual cues available to get you back on your front sight after recoil than there are to get you back on the dot after recoil.

Once you do get your recoil management working for you, you'll likely discover three benefits from a RDS handgun 1) You will be more accurate with the RDS than standard sights in the same time frame, 2) You will be as accurate with a RDS in LESS time than you are with standard sights, 3) Same sight picture all the time regardless of lighting conditions.

That has been my personal experience with USING RDS on handguns. As always, YMMV.

As far as which RDS to use...

From what I've seen, NO first generation sights work on handguns for a extended period. The first gen RMR was really about the only first-gen that held-up riding the slide. All the others would just get beat-up - some beat to pieces - when slide-mounted. Even the first-gen RMR had it's problems, not the least of which was the batteries would eventually begin to disconnect during use and the dot would become intermittent while shooting. There is a fix if you're stuck with one, however.

The Type 2 RMRs seem to have fixed all the issues with the first-gen and survive on a slide just fine. The DeltaPoint is a definite no-go for slide mounting, it's too wide and gets the crap beat out of it, then the lens falls out. The DeltaPoint Pro is looking to be solid, but be sure to use the metal frame that comes with it. The Holosun's also seem to do well, but some have demonstrated the same battery issue as the first-gen RMRs. Holosuns are also heavier than the RMR, not much, but at the forces the slide functions at every gram can matter so don't go cheap on screw quality, fit, or loctite. Docter sights have done well, too. They aren't common in the US but I've seen more than a few on handguns in Europe and no one was complaining.

Personally, I've only used RMRs and Docter on serious-use handguns and other than the first-gen RMR battery issue I've had no problems. I wouldn't hesitate to use a DeltaPoint Pro - especially with the protective hoop - and I'd be ok with Holosun as long as I was certain good screws were used and it was installed properly.

Another consideration is batteries. They live in the same environment as the sight and they have to be tough, too. Panasonic and Sony branded batteries do well. Duracells are usable but will need to be changed more often. I've not seen any other battery brand - especially generics - do well with a RDS on a slide for an extended period.

Hope this helps...