The launcher I made the theme for is still very much in alpha but even so it was clear to me it was exactly what I was looking for from a theme development point of view. It was written in a language that was already very familiar to me and has lots of resources for help, plus it's extremely powerful (I can pretty much do WHATEVER I want) and is still lightweight.
It's not ready for primetime yet though but it's getting there. LB is still a lot easier to set up and continue to keep adding to.
Anyway I didn't post the theme to try and cast shade on LB. I still think it's great - it just became a bit too heavy for my liking (and it's only on a single platform. Pegasus thankfully is is cross platform so my theme works on Windows, Mac, Linux, android (phone or a TV box like a Shield) or a Raspberry Pi.
Regardless, once Pegasus is ready for showtime I do recommend checking it out. I think you'll like it and I'm trying to get them to add LB support so if you have a launchbox build already you should be able to check it out fairly hassle free.