We use both Pentax and Olympus(Keymed) scopes in our Endoscopy units. I believe the staff there like the option of switching between the two manufacturers(Pentax & Olympus). I think they feel some scopes give a better image specific to the proceedure they are carring out.
I could not recall exactly like for like in terms of costing, I believe from memory(dont quote me) the Penatx service came out slightly more expensive, however with this all said and done, I was fortunate to visit Pentax technical facilities in Slough a good while back. Very impressive set up. We get good service from them and the repair turnaround is second to none.
Our OT's use a mixture of wolfs, stortz and the likes, but I believe most of these are rigids.
I hope this helps?