I picked mine up at the post office this morning and installed in about 20 minutes. Very easy installation and the instructions are easy to follow. Just make sure you fit the barrel to the action after installing the under-fold stock before you install the fore-end. There's a note with the instructions telling you to do this and why.
The Underfold Stock is definitely beefier than the factory stock, especially the fore-end. The stock fits tight to the action but not so much that it's difficult to install. The angle of the folder is such that it comes naturally to the shoulder making it easy to bring the sights into line. At least it is for me.
The lock is positive and the stock locks up nice and tight. All in all, this seems to be a very well built stock.
Sorry, no pictures. I installed it at work and my camera is at home.
Mine is a pretty tight fit into the sleeve without a scope, so I kinda doubt it would fit.