I figured I'd share my experiences with my newly installed M3 rear subframe bushings and swaybar.
HP Autowerks was great to deal with to supply everything, and Harold even answered when I had a question about using a shouldered bolt instead of OEMs.
Onto the install:
I made my own puller system to get the OEM bushings out and M3 ones in using 4" steel tubing and 5/8" Grade 8 bolts ranging from 8" to 3". It worked well to get the OEM ones out...but pressing the new ones in proved to require too much force for my puller, and I snapped 4 grade 8 bolts by the time I got the first one 1/2 way in. Lesson learned: You NEED a press! So I brought the subframe into my university's machine shop and used a big ol' press and they slid in like butter. For the front bushings with the square alignment dowel/pin thing, I perfected them with a 1" square rod.
The swaybar was as simple as loosening 6 bolts, slap on slap off. Granted, the entire subframe was out of the car and easy to work with.
Overall, this install was much much much easier than I expected. It's just using large tools to work with large parts and pieces. The only 'difficult' part was plugging the mid-brake lines. With the right tools, It can be done in anyone's garage without a lift.
Bushings: I was surprised how much I noticed these...especially when launching/shifting hard, you really feel the power without the absorption of the OEM bushings. Way more precise and less floaty. As for stiffness/roughness...I would compare it to changing the front OEM strut (rubbery) plate with Vorshlag camber plates...or going from 18" Non-RFTs to 19" RFTs. You feel and hear more of the road's imperfections, but I don't think it's much rougher. I would definitely recommend thesse to people who don't care if their car doesnt ride like a Cadillac and preferrs a more aggressive setup.
Swaybar: Wow again..... but in a different way. I thought the M3 rear swaybar was supposed to be the happy medium of stiffness, but in my opinion, it is too stiff for those of us without a LSD. Rallying around tight corners is guaranteed to be a one-wheeled-wonder.
All in all, It was a tough day installing..but definitely without too much of a headache.