Ionic poles are so much heavier at the bottom (base).
Why would anyone in their right mind want to buy a pole with a caution to use the top (lightest section), only as a last resort, (to maximise the rigidity of the pole). That's like buying a sports car and being advised to treat it like the family car, where's the fun of buying one.
I use SL-X and SL-2 poles because I know they are tried & tested by a window cleaner developing products to sell on to other window cleaners who live in the real world.