In reply to Smo: For god sake don't start asking questions about membranes as all very complicated and boring!
As for WS Softshell from using most fabrics i would say as a general rule they go like this;
WS Softshell = very warm, almost completely waterproof, completely windproof, heavy, not very breathable. (i.e. about same as a lightweight event jacket with a 200weight fleece on underneath)
Shoeller WB400 Softshell = not as warm, not as waterproof, fully windproof, not as heavy, slightly more breathable and feels far nicer (IMHO).
Powershield = colder than above, not as waterproof as above, still windproof and far lighter than both of above.
(standard) pertex = cold, as waterproof as a paper bag (once DWR wares off), windproof (ish), very breathable and far lighter.
i tend to run in pertex, walk in event/standard windstopper/powershield, climb in event or ws softshell and wear the shoeller to the pub (its far too nice to ruin
)
im a hot person so if your cold you might find this changes!