Just updated from v1.08b to v1.17.
Unlike others here, I have not noticed quicker boot up time, disc recognition time, nor load time. All are the same as before.
I tested this using 3 movies I recently watched; Close Encounters BD (both movie and special feature disc), Saving Private Ryan DVD, and Star Wars Ep II DVD.
However, navigation within the disc does seem smoother and more responsive. Trying trying a variety of controls (chapter skip, scan, stop, start, etc) and repeatedly loading, ejecting and reloading discs did not produce any lockups so far. I hope this means that the problem I was having (occasionally locking up when loading a disc) is fixed. This didn't happen very often, so I'll have to give it some time to see how it goes.
Testing Star Wars Ep II (I know this DVD has been used by others to test menu navigation and DVD layer change) the menu does seem smoother and more responsive but the layer change remains the same at 2-3 seconds.
In the past I had a problem with the sound on the Chicago DVD using the multi analog outs (v1.02). I was able to repeat the problem several times in a row before giving up. The next day I tried again and the problem was gone!
I happy to report that with v1.17 it is playing fine.
So my initial impression is that v1.17 offers better stability and smoother operation within a disc. I do not have any of the known problem discs, so I wasn't able to test those.
I am disappointed I did not get quicker bootup/disc recognition/load times and improved DVD layer changes. However, although I would have like to see Pioneer work to improve both stability and speed at the same time, given a choice I would pick stability way over speed. Afterall, speed means nothing if you don't have stability.
Ok, time to quit posting and go enjoy a movie!