Here are my first impressions:
Overall, the set is very close to what I expected. Not quite as thick as Topre PBT, but they feel solid and nice to type on. They are about as thick as the SP ABS doubleshots, but they feel more sturdy.
What I like:
1. Overall, they look and feel very solid. The set looks great overall.
2. The Universal spacebar fits my Leopold perfectly. I haven't tried it on my Filco yet.
What I don't like:
1. The Backspace lettering is not straight, as you can see in the photo. I plan to contact Melissa to ask for replacements.
2. The spacebar is a tad bit off color from the rest of the set, but not too bad. I believe that SP matched it as best they could, so this we can't do anything about.