Open Deck
USDM 2.0 WRX motor
If you ask me, this was designed as an performance economy motor. Although it has a large water jacket to promote effecient cooling, but lacked strength around the cylinders.
Semi-Closed
USDM 2.5 STi motor
Stronger with great cooling and economical to produce.
Fully Closed
JDM Turbo Legacy EJ22
The strongest motor design, but also more expensive to produce.
Also had cooling issues due to the small water jackets.
The main thing I wanted was the visual of the motor design.
I'll add more to this as I find more information.