javeryh,
What are you using for mounting screws when you do this from the bottom? Are those the concealed bolts with that cam nut you screw into the bottom? I think this setup bottom mounted would feel the same as a top mount routed and recessed. For all intensive purposes they are sitting at almost the same depth from the top. I was planning on doing this from the top, but countersink the plate holes on the U360s and use some tapered head bolts all the way through the material. I also have artwork and plexi to cover the entire setup, so no bolt holes through the plexi are required.
Nice routing job!
How did you get those corners? Chisel?
If I am covering with artwork I use something called a "binding post" which you can get at any Home Depot:

You do have to route out a little bit at the top to get the post flush with the panel. If you are covering with art you can just cover the post with bondo and sand it smooth. For some reason I don't trust the long-term durability of the cam nut thing you just screw in from underneath (especially in MDF) - not sure why though - I've never actually tried using them.

This was then end result:

I've also installed U360s with small 5/16" screws! Then I add blocks from underneath to fill in the space on top of the screws but I attach these blocks to the 3/4" part of the underside of the CP. The screws keep the U360 from sliding around and the blocks keep the entire thing pressed upwards towards the panel - not sure if I'm making sense here but I added the blocks because I had no faith in the ability of the screws to hold up over time.
As for the routing, yes I used a chisel to get the corners squared because I'm super anal.
