To be honest Kev....
We have three V6's and all with this modification including mine which is a full induction system replacement.
They have now been fitted for six month and we have had no issues at all with them... No splits, no vibration and no loosening of pipe or clips
The silicon bends are a little stiffer in certain areas of movement like crush resistance and side to side than OE which is to be expected from silicon hoses.... yet even more flexible in front to back than the OE pipe.... If the jubilee clips are decent quality like stainless steel, you wont have an issue mate, there is still plenty give for general movement in the system.... Bear in mind that when you get the silicon pipe, the legs are a hell of a lot longer than the one in my photo's, so even more give.... I just wanted to trim them down to suit the alloy induction pipe... IIRC , I trimmed at least 9 cm off
The only issue I can foresee there being is if the engine top mount would ever fail, then I don't think there would be enough flexibility is the silicon to cope... However... If a top mount got that bad, then that would be the least of my worries at a total of £23 to replace the pipe again
The problem with the OE pipe is that it's simply rubber and it eventually perishes and isn't flexible enough IMO with all those extra ridges that keep it stiff... That's something you don't need with silicon... Its like comparing steel components with carbon fibre replacements.