I've only recently started making wax melts in clamshells and as loose melts. So far I have used these waxes with great success, IGI 4625 Pillar Blend, IGI 4794 and GW 444 Soy and someone on here told me about them (and thanks to that person again). I have used the 2 IGI waxes by themselves, mixed 50/50 and also mixed each IGI wax with 20-25% 444 Soy. I've used different amounts of scent, from 6% - 10%, 10% seems to make the melts a little greasy unless it's the Soy doing that. Seems like they have all had great C&H scent throw. In my opinion, all the wax melts have turned out great. Except, I have been dealing with sink holes, not a deal breaker, and the 2 IGI waxes state they require a 2nd pour for level tops. But I don't like that the IGI waxes come in slab form and are hard as rocks.
In summary, the waxes perform great but are difficult to work with. I prefer to deal with flake or pellet waxes like the 444. I ended up busting those slabs up into 2 - 3 pieces and slowly heating them in the oven on cookie sheets. Can't heat them quickly, they turn into mush or liquid. Once they were soft enough I chopped them up into small cubes with a soap cutter (from the Dollar Tree, LOL, works great). The cutter sliced through them like butter. This turned out great and the wax is now easy to work with but it was a time consuming and boring process. In the future, I'm hoping to find a good wax alternative that is in flakes.