I just spotted this thread and still have a Miranda Sensorex II with 50mm f:1.4 and 300mm f:5.6 lenses which I bought used. The build quality of both the Soligor made lenses I have is excellent with smooth well damped focussing. Image quality with the 50mm in particular is excellent (I believe it uses rare-earth glass) and overall the Sensorex is an excellent user camera with a precision built feel and a lot of heft. It also has the benefit of interchangeable viewfinders and with metering using finders which were much more compact than the metering finders of Nikon F and F2. They managed this by mounting the meter cells behind the mirror. Oddly the metering has a bottom-weighted pattern. The only fault mine developed was a stuck follower needle in the viewfinder but then rare is the Nikon F Photomic with a working meter now and I prefer a hand-held meter anyway so it isn't a problem. The rest of the camera works perfectly with a quiet shutter and well damped mirror, all speeds being pretty accurate from the results I get. I think these 60s-70s Mirandas are very under-rated and cheap for what they offer - especially the EE models with selectable spot / centre weighted metering. It's a shame that the name was resurrected in the 80s by Cosina and cheapened.
I would back up comments re. the quality of the old Super Takumar lenses for the Pentax Spotmatic, mine were superb. The Nikon found favour with pros, not because of lens quality (although their lenses have always been good) but because they were the first to produce a total camera system, with rugged bodies, motordrives and every accessory you could need. The top priority for pros in those days was utter reliability in hostile conditions, and Nikon provided this.
Purely in terms of lens quality, my vote would go to early Pentax and Minolta lenses.
If you want a great place to send off your lens for a CLA, I recommend Vermont Camera Works. I live in NC and send my stuff to them.
One of the things that caused the demise of the Miranda Camera Company was the name, and I had to sell them for a living in those days.