5'10", 170-175 lbs. I rode a DU Nelson 138 for years. Switched to a 140 Premier and now ride the 141 Premier.
I think it just depends on how you ride. The most I spin is a 5. The larger board is good on straight airs and spins like b/s 180's. It feels like it would be a bit more to lug around on spins like 5+. But, Igor used to ride a 145 and he wasn't very tall/big. Collin Wright rides a bigger size too, and he seems to spin no problem. So, you can spin on bigger boards if you know what you are doing.
I also like the larger size on the colder, denser Tahoe water. Seems to be a bit easier on the ole' knees. If I had to pick a perfect size, it would be in the 139-140 range. Unfortunately, I don't get to design my own pro model so I have to go with what is out there!