1. Recoil Reduction
The Magpul doesn't reduce the recoil impulse. The Knox recoil reducing stock does if you use it the way they recommend. Many shooters (me) will get smacked in the face every shot with their normal grip/stance. For me it required me to change my stance so I sold it. No need to retrain myself for a stock.
2. Ergonomic---I know of no stock as ergonomic as the SGA---they're ugly as hell but feel and shoulder great.
3. Functionality---It depends on user preference.
4. Personal Pros/Cons--see above.
5. Satisfied with your final decision---Yup.
Answers in text above.