I've never used any motor other than a CIM on my team's drivetrains. CIMs are so popular among teams because they come in the kit, and fit with the kit gearboxes. Aside from that, they are also very nice motors with nice power and can fit into a lot of other gearboxes if needed.

Also, the drive train is usually low to the ground. Have you seen any CIMs high up in the air before? They may be nice, but they are a tad bit heavy (perfect for drivetrains, especially with all the support down there), and they are pretty decently sized, compared to other motors in the kit.

Hope that answered your question!

Keep posting these kinds of threads! I love them!