Wow that's a crazy looking keyboard!
The TextBlade has done a great job for me so far in terms of reducing movement and making all that easier. I think that's probably one of the number one things that I've heard from other TREG folks as well when going to back to traditional keyboards - the sheer amount of effort that it seems to take to reach all the way out to those keys that are way off of home row.
I've actually found most of the symbol mappings to make pretty intuitive sense so far - the number row at the top is right where it would be on a "normal" keyboard, and the symbols that normally accompany those numbers are the row right below it, so that's pretty awesome. Braces and brackets seem to be in a nice spot with the two index fingers, so I'm going to leave those alone. Same with semicolon and colon, since I'm used to those by now.
With regards to the other ones on the bottom row, I'm not sure if I'll just get used to them or if I'm going to want to end up remapping them.
As for vim - the little bar that gives you extra symbols while remapping keys includes the arrow keys, so you can make it so that the edit layer gives you vim-style navigation keys everywhere, on every system. I think that's pretty neat.
Escape is the top left of the green layer. I was thinking that I was going to make it so that I didn't need to use the spacebar to get to the green layer, but I've actually been surprised by this. First, the green layer stuff is really easy to get at, so I don't feel the same amount of motivation to move stuff off of it. Second, it turns out that most of the symbols are also on the green layer, so if you were to, say, be typing a colon after escape rather frequently, you could just hold down the space bar and hit the two one right after the other. Other letters after escape seem to come pretty easily for me as well, but you may still want to remap it out to the regular non-green layer.
E: Sorry for the wall of text, it seems that's how my thoughts are formatted on this topic...