I've used them both and also to owned the Ryobi knock-off of the Performax. They all work pretty much the same and give decent results as long as you don't ask too much of them.
If you want to do panels that are wider then the unit, you really have to have the drum dialed in pretty good. That being said, I think the Delta has a little better adjustment method than the Performax IIRC.
Take real thin passes and for finish work (vs dimensioning) once you get to the final depth setting, run the piece through a few times in different directions without changing the depth to really smooth it off. Alsi, if you stall it out from trying to take too much or starting with an inconsistent thickness board, it usually takes 3 or 4 passes before you can sand out the gouge. Make sure you sand it out completly or it will show up in the finish. I learned this the hard way.
Also, do have real dust collection, not just a shop vac. The shop vac can work in a pinch but these thigs load up quick and it will effect performance.
Note that they all suffer from overheating so plan your project schedule to allow it to rest a bit between jobs if you have lots o' work for it.
If I didn't have access to, or the money for a wide belt sander, I'd go get one of these right away. Once you have it you won't enjoy life without it.
BW