I started with dextrose many years ago and it worked fine. Then I switched and only used DME for priming when I would bottle beers. I did it primarily to keep any non-barley-derived sugars out of my beers (idealistic I know ), but I also felt like I noticed better head retention, finer bubbles in head, and finer carbonation bubbles as well. How much of this was just "imagining", I don't know but certainly some of it has to be. As for using wheat DME in a non-wheat beer, I have a feeling there will be almost no discernible differences from "regular" DME, but then again maybe you'll experience something new and profound
I've used honey for priming meads and have noticed different results as well. Larger carbonation bubbles, no head retention, champagne-like finish, but I'm talking about mead so maybe that just comes with the territory.
I would say: Give DME a shot. Let us know what YOU think. It's not going to hurt anything, that's for sure.