I am a poor window cleaner with a small round. I have only 1 pole slx 25 and 1 extension. I must say its a pain to add on. Take cap off 25, cap off ext. unplug hose, unthread hose, add ext, thread hose, add cap. When finished repeat. Takes a few mins at least. Also the extension was a good £70. a good part towards a new pole. Always handy to have a spare pole. Much quicker in my view.
Just buy two of these:
http://gardinerpolesystems.co.uk/parts/john-guest-fittings/metric-fittings.htmlKeep one on your pole hose in one end and a tail length connected to the other end with the male pole hose connector.
Then keep a spare length of pole hose with the other JG connector on one end (mine is about 10ft) long enough to accommodate the extra pole sections you want to add.
So there's no need to completely remove all the pole hose when swapping pole sections.
Just disconnect pole hose tail section from JG fitting, add sections and extra length pole hose.