It’s on my wishlist and I’ll be checking out the demo later.
[edit] I’ve played enough - essentially the first unmanned test flight - to know I’ll probably be getting this at release, so I didn’t want to spoil it by diving deeper.
I can’t say yet that it’s “better” than BASPM. It’s certainly a lot more streamlined. When SPM was released, Slitherine was making noises about a Mars-based sequel. I’m guessing it didn’t sell well enough to justify the cost of development.