5 gallon primary for a 5 gallon batch?

I am in the market for a new carboy since I lost one to stupidity (thermal shock). I was wondering what people thought about the method of primary fermentation using a five gallon carboy for a five gallon batch. Charlie Papazian suggests this to try in his book "The Complete Joy of Homebrewing"

The theory is that you'll sacrifice some volume for better quality beer because you will blow off tannins and such. I have a blow-off tube so that won't be a problem.
It would seem like there would be some yeast lost with this method, though. Any thoughts? Should I repace my 6.5 gal. or get another 5 gal. variety?

Well, I understand the theory, but I'm not sure I'm willing to buy that. The krausen falls back into the beer and ends up as trub anyway, even if it doesn't blow off. I think that I'd go with the 6.5 gallon to have the headspace, and not risk losing a gallon of beer by not having the headspace.

yeah, scooping the krausen or using a blow-off just to get rid of the tannins seems unneccessary. it all just turns to trub anyway. just leave it in the primary long enough for it to settle.

6.5 gallon bucket is much easier to clean and leave the krausen.