Vortex will serve you well.
I also have a Sig Sauer Romeo 5, which is contract made by Holosun for Sig, and It's proven to be a great optic so far.
My Vortex I've had for about 4 years, and it's ridden on shotguns, my AR, my 858, my 10/22 at one point. It's held up very well, no problems at all.
my Sig Romeo 5 has been on my 858 for the past year, and has done well so far, but I haven't exactly worked it too hard. I do like the optics better than on the Vortex, just not sure about long term reliability yet.