I think they are great. I have one on a 223 bolt action and another on a 22 rimfire. Very sharp and bright optics. You can see a 22 cal hole in paper at 200 yards with it. I'm not into adjusting my scopes up and down for range, these scopes aren't target turret. The adjustments seem fine and I've had no problem so far. The included sunshade is a great bonus. I was out on the weekend shooting varmints to sundown and the only rifle I could use was the one with the sunshade. The adjustable objective turns easily and smoothly and that was very important for making fast adjustments out in the field. For what I'm using them for, they are well suited and appear to be high quality.
There are many happy customers in the states. Read some review on Rimfire Central's web site. Most people are very pleased, but there is the odd one what had some problem, but it doesn't sound like there are many, and the warranty should be good for it for at least the original customer.
Not sure if its suited for a higher powered rifle, but its good on a 223 or rimfire. Great for punching paper at various distances.