Bose - I suspect the point Wrong Stuff may have been trying to get across is that your take off minima will likely be the same for both Perranporth and St Mawgan - as you quite rightly said it's the other end of the flight where an airfield's facilities tend to be important. I for one have certainly got airborne out of an airfield with no facilities, after negotiating with a nearby radar unit to pick up a service very shortly after take-off. Assuming you do fly in on a good VFR day, your rationale for choosing Mawgan over Perranporth in case you get "weathered in" is one I'd therefore disagree with, although I can well understand your other reasons for wanting to go there.