I ran about 6" on RE fixed lowers. The ride was crap. I had RE 3.5" coils with a 1.5" spacer, it sat at about 6". I had to slow down for every speed bump, pot holes sucked, the ride sucked, flex was just fine. I went to long arms and the ride is so much better. I can cruise over speed bumps with no problems. But then my 73 F250 handles speed bumps even better... My long arms are from Rock Krawler, which everyone says sucks because they mount under the frame rail, anchors, drag on everything, bob loblaw. I've drug them a few times, but it's never been a situation where I get hung up on them or where I could've made it if they hadn't drug.