Just another point of data. We have 2 CNC Studers (1999 S40 and brand new S41), 1 CNC Danobat (roughly 8-9ft between centers), 1 CNC Usach 300 ODL (about 12ft between centers), and a manual SMTW.
I love the Studers, they're easy to program, and run like a top. Our cycle times are great, but that all depends on how well controlled the previous operations are. We grind OD's and ID's, tapers, and recently contour grinding. Materials in a wide variety: soft steel, hard steel, carbide tungsten coating, other various hard coatings, aluminum, stainless, Inconel, stellite, waspolloy... We're a job shop, so high volume is not our game. We do not have in-process gaging, and don't need it for our lot sizes. We use digital snap gages with wireless transmission on most everything that is a straight OD.
There are a lot of Studers in US, I believe Honda had just ordered 40+ a couple years ago. Around the same time we ordered our new one. Our S41 has 2 OD spindles, both 20" wheels, and an ID spindle. Both OD spindles have integral automatic wheel balancing and touch-detect. Although, I don't use the touch detect for anything other than monitoring. Our process is good enough that I don't spend much time at all grinding air. My stock allowance is usually about .001"-.002" on diameter above the finish turn operation max material condition, so using the touch/gap detect wouldn't save much. Our lot sizes typically are from 5 to 10 pcs.
The only complaint I have about the new Studer is there are too many prox switches on our accessories! I can't put in the steady rest or tailstock without plugging a bunch of stuff in, and then having to tell the setup in the control that it is connected before I can do anything with it. Just adds a few minutes to every setup, where the old Studer had none of that. At the same time, the new Studer rapids at 800ipm vs 200ipm on the old one. It's much faster in all aspects. Probing is extremely quick, we probe often since we grind lengths often. Every machine has their quirks, and our Studers are MUCH favored over the other brands we own due to ease of running, repeatability, and overall ability. Studer is also very good with their customer service.
For what it's worth, on a forged steel shaft, we can grind OD's and ID's in the same setup, and average # of OD features is around 5-6, tolerances down to +/- .00015" on OD and ID, and we do a fair amount of ID taper grinding, with a +/- .001" on length between gage dia's, and an overall length from a gage dia to an OD shoulder, and we can grind all the OD's to size and ID to size in about 45-55 minutes (includes part change). This generic part would be about 3ft long, and 3-6" dia OD, with .0002" total runout on most features, and .0001" circularity on others.
Hope this helps.
Any Studer or process related questions, I'll be happy to answer to the best of my ability.