I wanted to share my personal experience and set-up with using OEM and aftermarket parts to rebuild or upgrade the front end of the XC90. These are my personal opinions and hope you can benefit with real world experience, rather than heresay. After driving BMWs for 20 years I wanted more from the handling. The XC90 finally went from boring to sporty.
If I didn't put it in the pic, the parts replaced are original Volvo. For my 3.2 engine mounts, I used all Hutchinson from FCP. I noticed on some of them, they looked exactly the same as the Volvo part, but the Volvo logo was grinded off.
The main thing to talk about are the control arm bushings. I had replacement Meyle control arms, but when a winter sale for poly forward control arm bushings plus an addition sale on top of it came up, I jumped at the opportunity. I used original Volvo for the rearward bushings. My assessment, I love the poly control arm bushings because they remove the bushing cutouts that flex and since they pivot in the bushing rather than twist the bushing when the control arm moves up and down, the geometry is more precise without the harshness. Yeah, each time the control arm moves up or down, the front rubber bushing twists. The poly bushings were a little firm at first and it took about two weeks for the bushings to break-in. Now they are wonderful.
For those looking to press bushings out of the old control arms, I can assume most people mainly fall between either you want the factory ride or sportier. If you are going to spend a typical $20-40 per bushing to be pressed out and replaced, I would go straight for the original Volvo or the Polyurethane ones. For bushings that carry so much load in the suspension, it is worth skipping both Meyle and Lemforder, especially if you are already going to pay for them to be pressed. Why save a few dollars when they will be on for 70-100k miles and are essential to the suspension.
The next thing I might change are the Zimmerman brake rotors. I think they have more ferrous (iron) material because they can form light rust in humid or wet weather. This means you feel grinding first thing in the morning as the pads clean off the rotors. I might try the Ate ones next time. The Bosch rear rotors don't have the same problem and I like them.
The last part I want to share are the subframe poly inserts. This is well documented, but if you live in an area that uses salt, I would skip the forward two inserts. The forward bolt threads are exposed to the outside elements and rust. Water and salt sit in the threaded part like a pocket, making it worse. Thus, I and others, have had these forward bolts break when trying to remove them. So, my suggestion is you can use the rearward two poly bushing inserts to help tighten things up and those rear two get most of the turning load.
The rest of the parts are performing really well and have been documented in other threads. They are of good quality, either equal or better than Volvo in my opinion. I love this set-up and with the right alignment, it works very well. It is civilized in normal driving, but really sporty on the turns.
The last bit that does not require parts is the alignment. I personally believe the factory rear settings are too toe'd in and this gives that front corner pushing feeling on circular highway offramps. Especially with the front end sport build, I noticed the rear was pushing straight/forward when I turned, so the trick is to reduce the factory (around) +0.17 of toe in on each side or total toe of +0.34. You can instruct the alignment shop to make it zero, or if you want a little straight line safety for the highway/towing/carrying 7 passengers/wifey/teenager, reduce it to +0.10 each side or total toe of +0.20 (still within spec range). This will improve the rear to follow the front wheels on turns and still feel stable at higher speeds.
Long-Term Update May 7, 2020
Besides the changed parts below, the rest mentioned in the original post are going strong with 33k-38k miles them.
-I changed the brake pads to Wagner Thermoquiet Ceramic pads. They perform better in cold, wet, and hot compared to Bosch Quietcast and Centric Posi Quiet Semi-Metallic. The Wagner TQ Ceramic does not have the dark brake dust.
-I changed to Bosch rotors and they rust less than the Zimmermans. I now only recommend the Bosch Quietcast or original Volvo rotors.
At about 17k miles, I started to get a creak when I turned the wheel at slow speed, like out of a parking spot. Around 30k miles of use, it changed to a small pop. Around 35k miles, I removed one front wheel at a time with the front on a jack stand, then I placed one hand on the strut/spring and the other on the control arm. I had a 2nd person turn left and right. I could feel the pop in the upper area and not the control arm, signaling it is not a balljoint, but the strut mount.
-I can no longer recommend Lemforder for a strut mount. While it did not completely break, it did make noise creaking and popping. There are other accounts of this in the forum too. The bearing also made [scratchy] wear noise at 38k miles when I checked it after removal. I have now switched to the Corteco strut mount and the noise is gone. Corteco comes with nuts rounded at its upper area, so have a wrench or deep socket ready, otherwise you can strip the nuts.
-I still recommend the Rein spring pad/perch. With almost 40k miles, these still perform well.