I've also bought and used some. My experience has been that they work fairly well- they are "softer" than Micro-scale, which has some upsides in terms of getting them to set, but they have to be handled carefully when sliding them off the paper or they "stretch" and I ended up with bubbles in cases where I was heavy handed. And per GhengisKong above, go with warm water and leave the MicroSet on the shelf.
The one downside I have had is that 2 sheets of decals were translucent- although sheets for other roadnames were opaque. It may be that this was on purpose for faded, weathered appearance, but nothing on their website or the decal instructions indicated this was the case. And for my purposes, I needed them to be opaque- or at least more opaque than they were. Meanwhile, the multi-color "Packerland Packing" decals were beautiful and went on perfectly. I will probably order more decals from them over time, but will be checking on the "opaque-ness". especially for white lettering.