My experience (recent as Jan) is with Canon Irvine, CPS gold.
Sent in a 5D2 and 1D4 for cms, had the 5D2 mode dial upgraded to the locking model - charge for that was $100, that's parts as the labor was discounted 100% to do the change.
Camera bodies came back clean, sensors both were very clean. Although the shutter count is listed as one of the points, neither body showed the count on the paperwork. I called up and they gave me the number for the 1D4, but didn't have one for the 5D2. I was able to get the count using FoCal Pro. I believe the count was correct - the 1D4 count matched Canon's, and the 6D count seemed about right.
Lens - they do no internal work - external clean, and I'd guess they check to see if the focus and zoom function, but I gather from many reports over the years the focus check is rudimentary at best - you'd need to request focus adjustment, and then you are into the tiered charges, as that is outside of cms.
However, you get free 2 day return shipping, so that and any paid work that is discounted makes it worthwhile to me.
I also sent in a 24-105 for cms and to replace the missing red ring...purely cosmetic, I thought. Well, it's kinda my beater everyday lens, and I hadn't even looked at it, was surprised to see the red ring suddenly missing - no idea how it happened.
They came back with a impact damaged barrel - cost would have been about $350, which I declined. I may get it done eventually, with 20% discount it's probably worth having it done.