Clever idea today. Word ladders, which connect a starting word to an ending word using intermediates where only letter has changed, have become a little overdone in crosswords, so these days it's important to have some new aspect. I really like Todd's idea here, calling it a WORD LOOP, and actually progressing from WORD to LOOP and back, forming a complete circle around the perimeter.
As with most perimeter puzzles, the fill suffers because of the high constraints. Each corner presents its own problem to the constructor, and even if he/she can get all the corners to fill decently, there's still the huge problem of getting everything to knit together. Typically puzzles can be filled from the center toward the edges, and usually each little edge area is not very constrained, so they're not that difficult to fill out. Trying to get four subsections to mesh together cleanly is a head-banging problem.
I do like how Todd's arranged his black squares to help ameliorate this issue. Notice how the grid is sort of cordoned off, forming a SW and a NE region, along with a barbell connecting the NW and SE? Very smart to do so, and it makes his middle region quite nice. Kudos for working in SVELTE and KEY WEST into a tough-to-fill area.
Due to the requirement of each perimeter answer being four letters, there are cheater squares in the NW and SE. That makes filling much easier. In the NW, Todd does a great job. Yes, there are a lot of RSTLNE letters, but I'm okay with that considering the cleanliness of the fill. The SE is a different story, with A DRIP and A TRIP crossing each other. Typically those are reasonable (if not pretty) answers, but crossing each other draws extra attention.
And the other corners, so carefully cordoned off as best as possible, also suffer. I love WE MADE IT! but not at the price of EBRO, OR ME, OBER all in that single corner. Same goes for NEWSWEEK and CARWAX, two great answers in the SW which bring the very heavy price of OGEE, ORNE, and AGRO all in one tiny space. It makes me wonder if Todd started in the middle and worked his way out, sort of painting himself into those corners.
All in all, an innovative puzzle, one I appreciated for its novelty, but also one so constrained that the trade-off felt a little shaky.