Standard OE RS ones are just normal gaskets like you get on any clio I presume - they are just made from normal gasket material, like a thin sort of metal IIRC.
PTFE ones are made in PTFE material which doesn't conduct heat; the idea being that the heat transfer from the head is reduced to the inlet manifold, so reducing inlet temps. The cooler the air, the bigger the bang. This is especially noticeable at low revs / sitting in traffic at idle when the air is passing through slowest.
The main financial and arguably beneficial joy of the PTFE ones is they are reuseable (should you want work on your inlets etc again or if you want to get under them, etc.) and also aren't affected by oil / petrol / high vibration etc so they will last a damn sight longer!
The PTFE gasket set includes inlet manifold and plenum gaskets plus x2 PTFE washers for the supporting bolts at the back of the plenum again to reduce heat soak as much as possible. Whether the washers make much difference is certainly arguable but in attempt to make every little count it can be seen as a 'may as well' addition.
Hope this helps.