So I just installed the timben SES FR150RB -P2. Just for another data point, I measured about 1.5 inches after install from bumpstop to axle. Very straightforward install. Taking out the stock ones is one bolt each and putting the new ones in is two each (one to hold bumpstop to spacer and one to connect to the stock frame spot. I highly suggest a racheting wrench though!! With my boat loaded the bumpstops rest on the axle (1.5 inch sag). I have a malibu 23MXZ. About 7500lbs boat and trailer loaded. It tows just as well as my old f150 with max tow package. For me, unloaded, I don't notice any change in ride at all, but when I plan trips to off-road I'll just take them off (doesn't take long). All said, it's the only option right now, and I think it's very acceptable. My 2 cents.