I've had 2 sets on my 1 truck. Explanation as to 2 sets. When the bushings started to wear, probably 4 - 5 years or so, (which surprised the heck out of me since they were Energy Suspension and I used red-n-tacky on them every 3 or 4 months) I contacted Top Gunz for replacement bushings providing original part number for the control arms. Paid whatever and when they arrived they totally were different size and wouldn't fit. Called Top Gunz and was told "oh you must have the old style arms". Needing to get my truck back on the road I purchased a whole new set of arms (keep in mind at that time they were only $209 +/-). When the arms arrived they looked the same to me as my 1st set. Upon closer inspection the bushings were indeed different sizes. I installed them and went on my way. I have to say installing tubular control arms instead of replacing with stock units is one of the best BOMBs I've done. That was about 5 years or so ago. I do it again in a heart beat. If they had the adjustable upper and lower arms back when I ordered mine I'd have gone with them for more adjustability. I recouped some of the cost for the new arms upon return of the new bushings that didn't fit the original arms. I figure when I'm ready to set up the 4 link on the Duster I'll use the old arms, we'll see how that goes whenever that comes around. Next time the bushings start to go I'll contact Energy Suspension and get replacements.
All in all I'd say they're good stuff and by the looks of what's on the website they've come a long way since I purchased my first set.
As far as the leveling pucks when you want to haul a load. Depends on the load, not being a wise arse. Example: when I hauled my daughter's 02 Sable on a two axle car carrier (U-Haul), loaded with her stuff both in her car, my bed and back seat from Philly area to Seattle area, about half way at a fuel stop someone said "your truck looks a little tongue heavy". I looked and said yea it does, but it's no where near the upper set of leafs (it's an 8800 gvw 2500) and goes down the road solid, straight, tracks true and stops straight. I'm a bit insane at times and one of my more insane moments was during this trip, my daughter was sleeping and I could see for miles in front and to each side of me, sky was clear and all conditions were ideal. From my standard cruising speed of 75 (speed limit 70, I think in some places it was higher but not certain) I tapped the cruise increase button (2 mph each tap) drove a ¼ mile, tap again, etc. until it wouldn't further increase speed at 91 mph (per GPS). It was far from the smartest thing I'd ever done, but it drove like it loved it. I didn't maintain that speed long, reasoning potentials, so I returned to my normal 75. So for the leveling pucks and my situation - they didn't affect my load, which I figured to be: Car (3500#) load in car (300#), trailer (2200#) and another 500# in the bed and cab put total load around 6500#. Yeah, I'm nuts and fortunate too.