I just got a can of Prothik and I like it much better than Fullmore. (Or at least I do on a single use.) It's "black" is actually black, and it seems to coat the hair less, which for seam blending is not what I really want.

So, I have to say that at the moment, I use Toppik, DermMatch, or Prothik, depending on the issue that needs to be corrected.

If forced to chose only two, I'd stick with Toppik and DermMatch at the moment.

The advantage of Prothik over DermMatch is that DermMatch is more work to apply, and also if after you've styled your hair, gelled it, and let it dry, you notice a little bald spot, the spot can be next to impossible to get to with DermMatch. If it's on the spot is on the top of your head, you can use Toppik, but as seam blends are more likely to be on the side or back of your head, Toppik doesn't work so well as it relies on gravity to apply.