There are a number of T4/B4/B44 drivers at my local track with threaded Losi shocks. They run them for two reasons. 1. They are a one piece design that does not have an easily breakable plastic top cap. 2. They say the Losi shocks are easier to bleed thus making them more consistent.
I have a couple of sets of Losi shocks and do like them a lot. However, the overall quality of the Kyosho shocks seem better to me, but they have plastic top caps like the AE shocks that break from time to time. I'm hoping someone will make an aluminum top cap replacement.