I use Tri Flow initially on the threads, and follow with Spoke Freeze when the wheel is complete, mainly because that is how I was taught, it's always worked very well, and Tri Flow is much cheaper than spoke prep - especially if you buy it in the gallon container. And I never consider a wheel build to be complete without the spoke freeze. True, if the wheel is in perfect tension at all times then a spoke will never come loose, but if you actually plan on riding on the wheel that perfect tension thing goes right out the window. Just sitting on the bike loads the top spokes while de-tensioning the bottom spokes. Now throw in your average trail...