I'm a bit worried that the rubber bit might perish and go sticky?? Anyone have that problem with a similar tap? We really like the pull out taps, but dont want a sprung one due to them having lots of gaps to get dirty... Its on the island so really want a feature tap just without the feature price tag!
I used to work with industrial rubber, and would never have it in a kitchen. There are many different types, and they all have various properties. Some are OK with water (not all) and a very few are OK with fats, but the ones that can cope with fats will not cope with water, and many of the water resistant ones will not like it a high temperature. If IRC silicone can cope with most things, but does not wear well.
Your worries are well founded and I think you are correct that you will most probably end up with a sticky, cracked tap.