Not a fan of Waller at all. Physically, he's impressive. Skills wise he's pretty terrible. Noted that he caught all 26 passes thrown his way. That stat is simply amazing to me, because balls thrown his way just look like they eat him up. Body catches a ton, and balls rattle around in his hands often. Watching him catch those passes is almost painful. QB play was bad. But Waller doesn't exhibit ability to get open, run routes, catch cleanly or make good adjustments on the ball. Benefited greatly by a run heavy offense where coverage was sacrificed for playing the run.
Has very little quickness. Very long strider who takes a long time to get up to speed. His best routes are go and double move routes. In fact those are the only ones you're likely to see any value of him on tape. When watching him run, it's like he has tacks inside his cleats. No discernable ability to sink hips and run curls/out routes. Very stiff movement wise.
If we're talking late round guy -- I'm much higher on Smelter. He demonstrates much greater movement skills. Watch some Waller, then watch some Smelter. Pretty confident you'll see two entirely different prospects from a skills perspective.