I started out looking for an aimpoint for my Stribog and was just really struggling with the high price of the T2 and/or CompM5. That's not to say I don't think it's worth it to some degree; I do have a CompM4 and CompM4s but in the end I couldn't wrap my head around a red dot that cost almost as much as the firearm that requires you to then also figure out how you're going to mount it, which height, etc.
Enter the Romeo4. Comes with two mount options and a riser to adjust either so you can hit whatever configuration you need. If that's still not enough, you can use aftermarket T1/T2/CompM5 mounts. I ordered a Romeo4T to get as close to that tank-like construction I was accustomed to with the Aimpoints and ACOGs I have. I took it out of the box and checked it out; it looks and feels like high quality kit and the reticle options are really nice - I appreciate the flexibility there.
I'm happy with the result. I spent half as much and got more. It looks fantastic on the Stribog and it's exactly in terms of the one mount you bought and spent an extra $100+ for.
So I say - if you want something in the realm of Aimpoint get a Romeo4; if you want something a bit less expensive, more in the Holosun price range, the Romeo5 is a solid optic for the money as well. Sig may be as much marketing as they are a firearms manufacturer but the reality is - the Romeo 4/5 at least - their stuff is the business. I would not hesitate, especially if you can find a deal online (rare for Aimpoints, not so rare with the Sig optics, especially the Romeo 5).
I will present one counterpoint: Nothing holds its value like Aimpoint. But if I'm taking $100 loss to sell either way, I do like the idea of tying up half as much in the product. So...maybe not a strong enough counterpoint to change things much.