I guess the jury is out on whether newer and well built rifles and scopes suffer because of Lead Sleds. Definitely something to follow and pay attention to. However, I'm not overly concerned at this point and will continue to use one as I have for the last 7 seasons, Remington CDL 30-06, synthetic stock, and Leopold VX 2 3-9x40mm scope.
For me, I think Lead Sleds are great for the initial zero and then checking zero prior to season. Saves time, money, and aggravation. That's all I use it for. Then I practice as if I'm in my tree stand or blind, simulating as best I can the same clothing, shooting position, etc..