I haven't tried these drivers yet, but when I tried Shadowplay when it came out a few weeks back, it seemed to work great, but it does have shortcomings. You can't choose your resolution - it's 1080p or GTFO. Which isn't necessarily a drawback, unless you're running a 16:10 resolution - so it will stretch your image to fit. Makes it useless on my 1680x1050 res monitor. There is a lot of call for that in the NVIDIA forums to change though, so I'll be surprised it NVIDIA don't implement that along the way.
Also seen a lot of people complaining that GeForce Experience isn't installing too, so I guess they'll have to fix that asap.