I may be something of a maverick, but I won't own a rifle that does not have good iron sights as a back-up.  That means that the optics (if present) must be quickly removable, and that the iron sights instantly useable thereafter.

The longer the iron sight base (distance) the better, and it is a very great asset to have a threaded rear peep aperture that will accept rear sight peep apertures of varying internal (peep) diameters.

Because of my eyes, I don't shoot so well with the usual iron sights  these days.  I generally use some sort of optical device.  However, if I can install a super small aperture into my threaded rear sight, I can do OK.

BTW, ALL of us over, say 35 years old, will find iron sights becoming progressively more difficult to use.  It's a fact of life, and NO getting around it.

II you plan on shooting accurately after age 40 or so, plan to use optics.

That said, the RAR is a fairly new platform, and so the aftermarket sight mfrs are just now beginning to offer decent rear sights.  Choose carefully, and always opt tor interchangeable rear apertures.  I'd opt for an aftermarket rear sight, that will accept common threaded apertures, and which will not interfere with mounting the optic of your choice.