The way I run these systems I don't end up with any equipment loss. I typically lose about 3% of total system efficiency in the trub before draining to kettle. Other than that, efficiency typically breaks down like this:
97% conversion efficiency. I lose about 3% of the theoretical potential still in the grains (this is typical)
78-80% lauter efficiency. That means I get usually about 78% of the available sugars into the kettle. The 20% that are left behind are in the wort left in the kettle on in sugars stuck to grains.
So after lautering I have about 75% potential into the kettle.
After the boil and chilling, I drain through a strainer into my fermenter.
I lose about 3% usually to hops absorption and trub, and a bit is left in the kettle typically.
As you can see, the easy improvement is to do a more thorough job lautering. I just take the fast route, since my time is generally more valuable than the extra two dollars in grain.