I know KVH has terrible support but they are the only manufacturer that has a HD solution (Dish) that also works with DirecTV. So it makes sense for me (DirecTV user) to buy the KVH and if the standard definition directv satellites are decommissioned and not replaced with HD, then I have the option of changing my receivers to Dish... I can do all of this without having to plunk down thousands on a new in-motion.
Also, if directv does go HD, these in-motions will be compatible (but the other models may not).
There is nothing else on the market today (as far as I know) that gives people this option. KVH is the only viable solution for in-motion if you want no risk of having to replace in 3 years.