F**kin Hell. The s**te people think up. Not you; you understand. Whoever wasted the breath to utter those words into your ear. :Meh: I had to check my calendar to see if it was 1st April there.
Several websites do actually include improved flow (slipperyness!) resistance as part of their PR for the sale of such hoses and that includes Samco. You pays your money!
Id love to see results from there scientific testing. The only upgrade when using Samco and the like is pretty colours.
plus, silicone has better thermal endurance, and withstand to UV than standard rubberised hoses (quick look on some databases shows much higher RTI (Relative Thermal Index) for silicone than vulcanised rubber, epdm, fpm, etc).
And I bet the difference between to two is miniscule with regard to flow. Don't get me wrong, if a hose fails Id go for silicone, but not for increased flow or because I worry about sun damage (I don't live in the Sahara ), its so I can choose a pretty colour.
Agree entirely on the flow, I believe the difference in flow is equivalent to the girth of a gnat's todger. Given the mostly low likelihood of exposure to UV due to them being hidden behind panels (and then cosseted in garages, etc) degradation due to UV will probably be very low. Temperature variation and exposure to chemicals/crud/oil, etc are more likely to cause degradation. My new hoses just happen to be a very striking blue colour ;-)