I've hit nominal efficiencies as high as 94% (though I think my LHBS habitually overrunning purchased grain quantities by a few ounces probably played a role too), and had some beers that were too strong for style but tasted too "blah" when dilluted, so I feel you.
I had to train myself to sparge less aggressively, that was kind of the deciding factor. >.> (Most of the styles I brew aren't harmed by an extended boil anyway. With some exceptions, IE my Irish Re...Aubur....Brown).
I found that, for a typical 5-6%, 5 gallon batch, ONLY letting myself fill up my 8.2 gallon pot for both mash and sparge helped.