Congrats on getting the deal!"thumbsup"
My Trailwalker just showed up yesterday! I wanted to get the "2 for" deal, but didn't have the funds at the moment, so I picked up just one of them.
As for the links, it looks like Element sells a 12.8 version of the rear links and a set of high clearance links in the 12.3 version. I'd bet that other manufacturers may have other options.
The stock electronics are ok. The reverse in the ESC is a little touchy. I ended up putting a HW 1080 ESC in my Enduro. I used the stock ESC as a servo winch controller.
The stock motor is really smooth! I am still running it and will keep it in there until it dies.
The radio equipment is decent for a stock radio. I am currently still using the stock radio in my Enduro. Eventually I'll buy another Spektrum receiver and swap it out to use my DX5C.
As for other weak points, I'm not really sure. On my Enduro I swapped out the c-hubs and knuckles for SSD right of the bat. These parts looked a little weak just by looking at them. The stock may be ok, but I didn't want to take any chances.
The shocks are really smooth and have not leaked a bit of oil. I think they will be staying on mine for awhile!
All in all, the Enduro has been a great rig and is one of my favorites to drive.
Looking forward to see what you do with your twins!