I have a couple of sightron's and am very pleased with them, though not perfect.
I looked hard at the 5-30, but after reading a review by
@BigJimFish, where he reported poor glass quality (I understand it was an example of one) gave me pause, then I looked at the specs, only 23.5 mils of adjustment, turning it into a short range scope, I decided to pass.
A shame, I've talked to the folks in Florida a couple of times, seem like good folks, but they can't seem to put all their shit in one sock. They are always just missing the boat on the tactical scopes.
I have one of the very first S5 4.5-28 scopes that came in to the country (number 12 of the first batch). The glass is great, but the locking knobs are extremely difficult to lift. It does not have a zero stop, but I knew that going in. That being said, it is one of my favorite scopes, very easy to get behind. I had high hopes for the 5-30, but they scared me off.