Build 9926 was pushed to me last week and it looks pretty neat with a few functional changes and new icons.
This one is more buggy than previous builds for me. For instance, the Recycle Bin won't empty and when trying to do so it takes many seconds to respond to the clicking action.
The resolutions changed and it doesn't fill up the iMac screen like it previously did, so I had to reduce it a lot, though it did make it a lot easier for me to read with the bigger icons and font.
I looked through the MS Feedback app and I'm not the only one experiencing that. A couple of other people with 27" iMac's and VMWare Fusion 7 have the same issue. Plus, the font and icons even look a little fuzzy now.
When booting it, it gives the opportunity to continue with the new build or rollback to a previous version which is cool. It now has a search bar by the Start button and Cortana too. Cortana seems pretty cool and they've beat Apple in bringing a personal digital assistant to the desktop, since OS X only has dictation and not full Siri.
I'm still poking around with it a little bit at a time, but I am enjoying it and I do look forward to Windows 10 later this year, and that it's supposed to be free!