We haven't experienced the dimming - but we are also primarily incandescent. For the mini's however - this is our 2nd year to use conical 50 light sets 6" spacing from Deco and we love them. Perfect color, good reliability (so far).
Leco is the same as Orman right? We've ordered a few things here and there from Orman - usually when we're in a pinch late in the season. A few red and green LED C-9s last year -- we were pleased, but not any LED minis.