Trailmaster,
I think you could get a lemon in any brand. I had a Tasco that did good for 4 or 5 years then went bad. They replaced it, but it took about 3 monthe to get the new one. It zeroed fine , but then quickly went bad. I don't think it could handle the ATV rides.
I have a Leupold V-II on my 7MM mag now. I do have a Simmons Atec on another rifle too. I have not used the Atec that much, but it is certainly not as clear as my Leupold.
For the slight difference in price, I'll always buy Leupold from now on.
For the money they are probably the best scope you can get! Good luck!