I put together a very rough overlay of the RMR on top of the SRO based on the comparison photo floating around.
The window looks HUGE in comparison, but it looks like the footprint of the optics at the widest point isn't really all that different and I think I could conceal this AIWB fairly well.
I'm pretty glad that I returned the RMR that I just bought and will probably pick one of these up. Eventually the RMR will move to my training gun since I think training with the smaller window could help refine skills even more.