I am another 135mm Componon user. My Beselers will (just) extend fully without hitting the ceiling, but if I wanted to use a 150mm I would have to either drop the bench or use a step - I'm not that tall. Even if the 150mm offered better overall performance, I would have to temper that with ergonomics. I like to have a good working environment for the 'bread and butter' sizes between 10x8 and 11x14. If I was routinely working larger I might make a different choice.
I also work in other formats - 75mm for 6x4.5 or 6x6, and 105mm for 6x9 - so the general setup needs to respect that.