Right Engine Gear (Metal Semi-Flat)
Spin Gear: Right Engine Gear (Metal Semi-Flat)
More of a small flat tip rather than Semi-Flat, as the edges aren't bevelled.
Moderately aggressive movement, but not all that much.
Final Clutch Bases are generally better than First Clutch (which tend to break flower pattern or even Self-KO), only due to the chance of a desperate last minute attack which generally lacks the speed to do anything but sometimes even manages a loose flower pattern. Were the available bases less tall, this might have been useful with an Attack Ring like Square Edge, however Engine Gear setups are too tall to make use of it.
Overall though, a lighter and less bulky Normal Base (Wolborg 4 Version) or Normal Base (Rock Bison Version) is generally a better way to go unless you want to show off the EG Gimmick. In this case it is best to not wind the EG.
Right Engine Gear (Metal Flat) tends to do everything Metal Semi-Flat aims to do better, making it heavily outclassed.