High gravity: Multiple Fermenters Instead of Blowoff Tube?

My LHBS recommends, for beers over 1.060, splitting a 5-gal wort between two 6-gal vessels to provide headspace enough to avoid the need for a blowoff tube.

I've got an Old Chub clone going now (this one) that is at 1.078, and because I've had blowoff issues in the past, I did the two-fermenter thing this time: basically 2.5 gal of wort in each, one packet of US-05 in each, to be reunited sometime after primary fermentation.

Aside from the increased infection risk of two vessels, what would the downsides be to this method, versus just installing a blowoff tube on a standard 6.5-gal pail or 6-gal Better Bottle?

Also: I generally don't secondary, but in this case I'm tempted to, if only to get a fermenter back after primary fermentation. OTOH, I will be kegging this one, so I'm considering dumping both fermenters into the keg and "secondarying" there before chilling in the kegerator.

Opinions?

-Rich

Well it should be good the way you are doing it.
I've got some good eight gallon buckets with O ring gaskets that I use to help prevent a blowout.
With that high of an OG I would probably still use a blowoff in the bigger bucket.

I would rack them both to one container to secondary them also. If for no other reason so that they blend and any slight differences you may end up with will be taken care of.