I installed it last night right before bed and made sure it worked but reverted back to the normal launcher before I went to sleep, just in case. I didn't have time to properly play with it and set up my screens. I also realized that in my usual groggy morning state, I should probably leave it on something familiar.
It certainly looked cool but that might just be the "new-ness". I did just play with it now to see how many screens I had. There wasn't the usual settings page to add screens but if you drag an icon to the right edge, it'll move to the next page. (Out of the box, I had two screens plus the Now screen.) The screens it came with all have something on them. This is important from what I can tell. So dragging an icon to the right edge of the second screen caused another screen to be made so I could put that icon on it but it won't add yet another until you place something on that empty screen. Smart. So far, I got it up to six screen and haven't tried adding more because six is already excessive to me and I haven't tried seeing if I can delete screens yet.
