To my knowledge no Sig RX model comes with a plate...unless you count the wierd plate on the 320 X5 that can only be on when the rear sight is used.The only thing that sucks about the SAO versions is that the slide stop/release is right next to the thumb safety that protrudes out which would make it difficult to manipulate.
View attachment 39241
You'd probably have to manually rack the slide back on a mag change which might be difficult to do with a red dot without getting oil from your fingers all over it and possibly blurring your vision in the optic or accidentally hitting one of the buttons on the red dot. Just thinking out loud here. If it were me I'd still get a SAO version with the red dot if it were just for HD use and put a light on it with a 20rd extended mag.
Do the RX models come with a plate that you could put on it if you decided to take the dot off?
This would be strictly a house/range gun...
I just keep thinking how that $300 is a case of ammo...and maybe a light