I have no problem centering either.
Set it approximately correct when you tighten the installation bolt, then use the centering adjustment screw for fine tuning.
If it is too far off for fine tuning, readjust the main bolt. Once set, it stays put. I even have some wheels that are dished a little "off" that I just use the centering screw to adjust for when I use those wheels. No problem.

BTW: I have been using them with the stock pads up until about a week ago (on aluminum rims). They worked fine. But I put in some Swisstop Green pads last week and they are noticeably better. The Greens don't "glaze over" and maintain a nice, quiet grip with great range of precision modulation.

I use blue reynolds pads on my carbon rims.

Whilst everybody compares the stopping power to DA, Red and Record, how would I find them compared to old 9sp 105 calipers?

Also, are they durable enough to last a number of years without any specific cleaning and servicing?

Thanks.