CMT have done some really good stuff over the years, although anybody who has played SPv1, and the later, more rushed missions of SPv2, will attest that they've improved a lot.
Personally, I'm not a fan of the extremely overdone Plasma Rifle projectiles, but aside from that, I'm hyped af for these maps to go public. I just hope CMT aren't being too ambitious with this project, like when they disbanded halfway through Halo 2 evolved.
I loved TSC:E, especially how the weapon sandbox wasn't just "find the nearest mid range precision weapon and destroy everything. The loadout selection was a nice touch, too, and made sense as you were being supplied in the Pelican. The fact that they're adding some gameplay-altering features like gravity terminals is pretty nifty imo.
Outside CMT there are some pretty cool mods. Z Sanctuary H2 PB2 has the most functional, least bug ridden Energy Sword I've seen appear in mods, and the little party room is a classic gag. Yoyorast Island was a nifty map, although v2 could really have done without the WWII Poster Girls, because shit's just weird.