You listen to rannestad's recommendations.
After reading one of his posts and exchanging some private messages with him, I ordered:
1. A Canon EF-S Precision Matte focusing screen
2. A KPS 1.3x Eyepiece magnifier
I cannot fully explain how SATISFIED I am with the results. The combo has improved my ability to focus with my 3G by an immense amount. I can clearly see where the sweet spot is and how it moves around even wide open.
The EF-S makes the bigger difference in that it shows you a MUCH TRUER representation of what the sensor will see in terms of DOF.
The KPS seems to be an excellent quality magnifier, I don't notice any significant vignetting in the corners and having the bigger view is VERY NICE! I would definitelly advise AGAINST this for anyone with Eyeglasses though, as far as I can tell it makes the viewfinder unusable with glasses.
Anyway... a BIG thank you to Rannestad for pointing me in the right direction!