I hope this doesn't become another Sig bashing thread...
I have looked through a Sig Romeo 1 Pro at the gun club. I have shot with a Romeo 1 and a RomeoZero. All of the above seem to have more of an amoeba shape to the dot than round. Trijicon and Holosun appear to have a nice crisp, and mostly round dot to my eyes.
I put a Sig Romeo 5 on one of my wife's AR's and it seems to have as good a dot as the MRO on my Recce14. Nice and sharp.
Do Sig pistol optics have a blobby dot to anyone else, or is it just me?
On a side note, the RomeoZero dot is tragically distorted on the brighter settings and gets worse when the dot is aligned with one of the lens distortions. When turned down it is a little less of a fucked up mess.