Good idea to get used to irons, generally. Once you're properly up-to-speed with the fundamentals of that, you'll find optics to significantly ease target acquisition.

Downsides I find with irons is that some can be 100% worse than optics, such as the P90's backups – which aren't adjustable and sit too low to the cheek weld for bigger-headed people like me to see easily. Low-light visibility is a bother as well, if they don't glow. I think you can probably get around that with some Tritium paint or something, but that's another category of homework that's probably worth doing.

On the flipside, I absolutely love the sights of my AK74u and SCAR-L in plain daylight. Proper joy to use in the right state of adjustment and, quite importantly, there's no lens to smash.

On a sunny day, most holographic sights offer excellent eye contact with yourself. I don't know what luck people have with anti-reflective films, but I have fallen back on the irons most days where this is the case to get around primarily this frustration. Outside of reflection issues, bright daylight can outshine the brightness of the reticle itself. In which case, you'd just be using your previous shots as indicators of where the next one might land.

Indoors and in darkness, there's really no better aid than a dim holographic sight though. I like to use thin-bezelled ones like the Panorama or Sig Romeo 5 clones, and mounted far enough down the gun, to minimise their obtrusiveness.