As it happens, I just installed the Energy Suspension poly bushings today. All I can say is WOO HOO! It's like driving a new car, no lie. The ride is not too hard and I have no squeaks (although I only took her out for a fairly short, if spirited, test drive). This is the BEST handling mod I have done so far. It made more of a difference than the HO/F-body sway bars (probably because with the poly bushings they can finally do their job the way they are supposed to). It also appears to have cured a very annoying problem I was having where my headlights would shake every time I went over a rough stretch of road, and I think it fixed my outside rear view mirrors too, which were vibrating whenever I was driving at highway speeds.
The installation was a major pain in the ass. I figured it should take about two hours so, of course, I doubled that in my planning. All in, it took about five hours from start to finish. (Maybe I'm slow, but I don't think I could have done it more than about a half-our faster even knowing what I was doing.) My only regret, though, is that I didn't make the time to do this last Fall when I ordered the kit in the first place. Whichever way you go (Dal or ES), I would recommend that you buy a few new bolts from Dal or Sam, as well as new metal cups/sleeves (I don't know what else to call these -- they're like a cupped washer with a sleeve attached and they go over the top bushing (in the #7 and #8 positions) and the sleeve goes down through it, or under the bottom bushing (in the #1 position) and the sleeve goes up through it) for the #1 position bushings (up by the radiator) and for the #7 and #8 position bushings (at the rear). I got new bolts but didn't get new cup/sleeve things, so I had to do a little work with the bench grinder to clean off some rust on the ones from those positions. My car has been in Connecticut all it's life and those were the only positions where I saw any problems.
Bottom line for me is, I LOVE this mod.