The Oly has the fully electronic shutter option at the different speeds and it's loads of fun. It sometimes warps the images but it's worth it. By keeping it in high speed silent shutter mode the whole time I took thousands of photos at this event without even fully realizing it. I was actually using it at times in long bursts while moving focus in and out as a way to spray and pray... The buffer was never an issue either that I noticed..

Is the Oly noticeably quieter than the K1?

These have come up very well mate. Brave of you to take the Oly but it obviously knows who's boss. The high ISO response is great and you've done great with the focussing. A beaut. record of the event and H's parts in it.