I have used the Burris FastFire and Trijicon RMR, and I think the FastFire and Doctor take the same mount - but verify that.
Personally, I prefer the RMR if only because there is no "on" switch and it is ready to use when needed.
These sites take some time and effort to get accustomed to, but are quite fast and accurate once you unlearn traditional site alignment and site picture.
My singular piece of advice is to only mount one on a pistol that indexes, for you, exceedingly well. The window is small and getting the dot in that window can be a challenge, unless you index well.
The RMR is more than the doctor and the fastfire, but that is for good reason.
I do not buy Leupold products so cannot commend on that option.