I just replaced my stock front struts at 81,500 on my 2002 325i wagon with the Meyle's and they are working out well. They are identical in every way to the Sachs that came off the car but have matte blue finish instead of black. The tower nut is a 19mm rather than the 21mm that came off the Sachs but the piston itself has the same diamter. At $90 each I bought them because they are inexpensive stock replacements and my E46 wagon is a daily driver for my teenage daughter. Performance is not a consideration, I'm after low cost, reliable, stock replacements. My stock struts could have probably gone a little longer, they were not that bad, but I've recently done the CA bushings and need sway bar links so I thought the struts needed to be done as well.
I also replaced the strut mounts with new Meyle's because I thought the stock mounts would be worn out. Turns out the original mounts were in perfect condition, I could have easily reused them. There is one slight issue with the Meyle's that's a little annoying. The stock 32mm mount caps do not snap into the mount holes because the Meyle's are just a hair bigger, perhaps 33mm. I don't see that Meyle makes caps so I will have to find a 32mm o-ring to stick on the cap to make it fit snugly. Until then, the caps are just kind of sitting there...
So, the bottom line is the Meyle struts are perfect stock replacements, they ride well and are inexpensive. I do not recommend the Meyle mounts because of the weird sizing that won't allow the mount caps to seat.
As for the swap out job itself, it was high on the suck-o-meter for a while while I struggled with the spring compressors. I was close to giving up and taking the springs to a shop to get them compressed. I used two of the single bolt type from ECS Tuning and it was a battle. Most DIYs recommend using them 180 degrees apart, which means one side grabs two coils while the opposite grabs three. I found the two coil side bottomed out too soon and couldn't compress enough while cranking down on the three coil side resulted in an uneven compression that wouldn't allow the top or bottom of the spring to seat correctly. After a couple of do-overs I decided to move the compressors to more of a "10 and 2" position, jamming them as close to the coil ends as possible in order to grab three coils on each side. This worked great and allowed me to get the springs compressed evenly, with plenty of room to work, while seating both coil ends nicely on the strut base and top hat. Strut #2 went much easier and now that I know what I'm doing I wouldn't hesitate to do it again on my own.