Definitely works really well and is peppier than 3.4.2. They’ve cleaned up some of the code in it and it shows. Definitely good enough to deploy to your blog. Note: It doesn’t work well with DiggDigg plugin so you’ll need to find another. Cheers. Percy
If you run a blog, the 3.4.1 upgrade was a complete mess of an upgrade. 3.4.2 is another story. Many bugs fixed. This one is finally worthy of upgrading to. I haven’t found any major problems so far in my testing.