Dang, sounds like you have a nice operation. You must have some decent sized equipment to do 10 gallon batches. Do you just use two carboys per batch then?
A lot of people on homebrewtalk swear by using primary only, and leaving it there for 4 or 5 weeks. They say the yeast cake settles enough that none of it gets suspended, it cleans up ALL the yeast, and really has no bad effects. The few times I've done it, seemed to be fine.
I started on a extract kit about 5 years ago (i bought the kit for my brother, and soon thereafter bought one for myself). One of my friends in Brooklyn owned a bar and wanted me to sell him kegs (underground, for his loyal customers only, never panned out for fear of the fuzz) so I upgraded to the 10 gallon batches. 10 gallons was as big as I could go as I was in a small NYC apartment and didn't have an outdoor burner. (I used all 4 burners on my tiny gas range, it actually worked really well). I now have a 15 gallon boilermaker, a 15 gal megapot and 2 10 gallon rubbermaid drink coolers. I literally had to rent a storage unit in brooklyn so that I could store them, pita. Anyway, I love having a garage and an outdoor burner now (really reduces the time to get things up to temp)! For regular gravity brews I'll make a 10 gallon batch and then split them into two carboys, usually trying two different yeasts. I made a wheat beer last time and used the american wheat yeast in one and a german wheat yeast in the other. Difference is pretty amazing. Occasionally i'll dry hop one, and just keg the other. The ability to experiment is the best part about the 10 gallon batches. If I'm doing a high gravity brew I usually keep it at 5 gallons or so since it's easy to run out of space in the cooler.
I'd love to get a 14 gallon conical fermenter, but my wife would probably kill me as she knows how much they cost. Cost keeps going up on the off-brand versions too unfortunately. In the meantime I'm a big fan of the better bottles. Easy to move, easy to store and much less likely to break. I have my original glass carboy that I use with care for anything that I'm planning on having in for 6 months plus, but the rest go into the better bottles.
I'm getting ready to do another no boil beer (lacto fermented berliner weiss, decoction mash) soon. These things are easy, and berliner weiss is awesome for the summer (low gravity, tastes like beer lemonade, without actually being a shandy)...