When it comes right down to it, there is considerable cost over a stock P07 or P09. The RMR is over $400 and the work to make it look like these do it almost as much as I paid for the pistol a couple years back.
But once you shoot it and you see the advantages of the sight in speed and accuracy it makes it worth it, to me anyway.
The idea, of this type of pistol is to be able to hit the target quickly and effectively. This set up makes it easier for me.
I've seen/read some people claim that the "dot" is slower than the iron sights. They say they have to hunt for the red dot when they present the pistol to the target. I'm not sure how your pistol, if you've got the right grip and have practiced with it, is any different than with iron sights. I've talked about this before. When I was carrying my M&P FS 9MM I changed to the large back strap insert and only noticed it fit my hand wrong when aiming some place beside straight/level in front of me. I had to find the front sight by waving the pistol around. My 1911s are "right there" no matter the angle/direction. It was the large insert. Felt good in my hand, but threw the angle of the gun off. I went to the medium insert and everything was cool again.
If your front sight is there when you raise your pistol up, or when the pistol recovers from recoil, the dot will be there.
Practice with the dot, just like you practice with the sights.
I was afraid (a little) at first that my mind (easily confused these days as I am) would stumble when presented with the iron sights I'm used to vs. the dot I'm not used to. That hasn't been true. The dot is brighter, in all conditions, than the FO front sight and it grabs my attention immediately.
Now, I don't shoot competition, I just shoot paper, but for me the dot is helping me shoot better.
I don't think dots are a fad. S&W and Glock make some of their models "dot ready" from the factory. I read, on the internet, that there are problems with some of these guns if you want to be able to co-witness with the dot sight or use the irons as a back up vs. just ornamentation. No such issues with either of mine. Now I did not try to sight my P09 in to have the dot and iron sights have the same POI. The iron sights, with my 115 grain loads, shoots a little low up close. I adjusted the dot to put POI higher, so it is on POA up close.
There are companies out there that will modify other brands of guns for dot sights. The idea is growing.
I may try a Delta Point Pro next time. I bought a couple of the rear sights that go on the Pro (ever use that excuse? Well, I've got a couple magazines for a P09, so I should get a P09) and if they keep getting good reviews one of those might be my next dot sight purchase.
Which ever direction you go (back up sights, no back up sights) or dot sight you buy, or what pistol you put it on, good luck with it.