Alex, our pole weights are with out adapter and base cap, as these attachments can/will be changed. I imagine you weigh yours without them and ours with? According to our scales, what we've published is pretty much what they are, with a variance on manufacture.
Weights are really just to give an idea of the pole, it all changes when brushes/hose/aquadapter are added for actual work. Anyone and everyone I've spoken to who holds a SLX18 and a Phoenix 18, for example, say they weigh the same.
Our 'equivalent' poles maybe a slight bit heavier (in grams, yet to confirm this) as we have, I believe, more carbon on the pole due to slightly thicker tube diameter than the SLX. This gives more rigidity to the Phoenix X over SLX as you have seen.
Glad to see you are a good customer of Facelift! How are you getting on?