Well...a year and a half later, the e-track is working out great.
I put 2 rows down on the floor to tie the quads down with, and it works perfect. I really like the versatility of this stuff. Like whiterhino mentioned, the tracks do get packed full of dirt/sand after a while...but it was easy enough to take care of with a shop vac once a season.
I also ended up getting a bunch of the Gladiator garage organization stuff like I mentioned from Lowes, I put 4 rows of the track on the front wall, and one row of it along the roof on one side.
These pics are from when I first got everything installed...I have since added a few more hanging baskets along the one side, and quite a few more hooks to keep everything organized and off of the floor. It only takes a second to move the baskets/cabinets...so this stuff works out perfect for a trailer.
Track on the floor:
gladiator stuff on the front: