hi 808, i have the crown moulding stops and like them very much. i do not use a saw helper, but i have seen them being used by various chippies on youtube.
here in oz, the most popular dropsaw bench is made by a company in brisbane, they are called a "tommy tucker bench". i use it with a makita 10 inch dropsaw evrey day and it is a great piece of kit.
very solid aluminium bench, lots of roofing and framing chippies use them too.
i made my own custom mdf bench for my kapex and then decided to buy the crown moulding stops, they do increase the amount of timber you can place on the kapex, but they are very expensive.
you can still work perfectly without them, it all depends if you can justify spending all that beer money on another festool toy!
regards, justin.