Looks great! I really like the fact that you now have the choice to make the titles completely transparent so that don't even appear as tiles anymore. Now you have the option to make your phone look just like icons like iOS or android. But with a twist, they are still live! Now Windows Phones definitely have the most customization no one can argue that!
Okay, after a lot of testing, I have discovered this:
Don't cut images to your native resolution. The OS is reintroducing parallax scrolling, which means your wallpapers need to fill a gutter partway off the bottom of the screen into which the view can move. If the phone is given a 1080p wallpaper, it will stretch it to a large size to fill all this space, making a blurry image. The screen will also use the rightwards space to scroll a little to the right when entering the app list menu.
So, your wallpaper must be 1297 (width) x 2300 (height).
Here's mine. The image is one of a series of 3D renderings of someone's idea of how the Chinese Pak-Fa fighter jet might look. I have played around with it a bit, adding the ocean/beach look to the background and resizing the aircraft to fit in with my icons a little better. I had to adjust it over the weekend to accommodate the new parallax style in Build 10136. I also put a tiny bit of transparency back into the tiles, just to ground them a little bit better, but I think that eventually Microsoft will sort out the tiny icon issue, at which point I wont' need to see the tiles at all.
I have it to my Lumia 920 and its my only phone. Its pretty stable, with fewer bugs. For me they aren't annoying or a deal-break, but it depends on the usage. So far i didn't have any random reboot or a major crush, bug. But this is my personal experience. I don't know if in a different model or in a carrier phone will work the same. But i saw in video reviews that in the newer high-end phones like L930 or L1520 the w10m 10136 was faster.
So here are some features, bugs
I haven't had any problem making calls or answering, getting texts but there are app crashes, like messenger, viber ( i can receive notifications, but sometimes both apps crashes when i try to type a message).
The new store is stable enough, it is a bit slow but its better than in 10080. All new universal apps age better (To see the changes first update all the new apps from the beta store). Although i faced a problem with outlook mail, the app for me couldn't open at all (since Friday it can). The calender works finel.
The music app and video app are awesome and feel solid. Like the map app (i don't know about car directions as i don't drive). I have no idea about games, as i don't play any.
The office apps are very good and useful to make changes to documents. I dont know if excel is helpful.
And now about cortana. She is simply awesome. She has a fresher UI much better and more mature than ever. She now takes better commands than in previous builds and she is faster. (but cortana's live tile is blank. It doesnt show anything)
About spartan. Hands down the best browser ever. It is fast and fluid. The reading mode is great. (We can again download photos.) About UI
The scaling bug is gone. The elements, icons, letters are big enough. (Although i loved the smaller ones).
The UI is more consistent, unified. It feels fresh.
The action center is better than before. They changes the icons and also the gave us the ability to swipe down to make the extra toggles appear and swipe up to disappear. (sometimes it doesn't work and may feel a bit sluggish). To open the toggles you can now swipe down and swipe up like you do with the cation center. (it doesnt work always).
The resuming isn't gone entirely, but i don't see it very often. I usually see it at the startsceen when an app is crashed or something like that.
To sum up. For me the phone works great with the 10136 build but it depends on the usage. The battery is good enough for a medium-light use.
P.S. If you upgrade to the 10136 check for new updates. I got a new one that fixed a few problems and made the phone even more stable. Some say that doing a hard reset will make the experience smoother, but i haven't tried it in this build so i wont advice you to do this. And last but not least update first the store app and then the others. The new store app version is way faster and stable than before.