Hi Colin, to answer your original question, I would go for the slx extensions then when you maybe upgrade your clx you would have a all carbon pole that would clean upto 35 foot. Hope this helps. We have slx ext 6,7,8 on a slx22, we could of got away with 2 extensions but having the 3 means we can 3/4 extend all the sections which makes the slx super rigid at the higher heights, Regards, Dave.