i did 30 odd miles last night , no problems, everything working fine , i did notice the heater took slightly longer to warm up than before, and once warm, its hot, but not scorchio like before.
i suppose the coolant was hotter with the dodgy thermostat, and most of the cooling was being done by the heater matrix rather than the radiator.

the car had been lying for about 5 months before i bought it and was only doing one or two thousand miles between MOTs laterley. meaby this contributed to the sticking stat.

so beware ! if your rad fan is on most of the time, get it fixed even if the temp gauge is normal.
eventualy something would have given on mine with a sticking thermostat, and it would have been expensive, and the only symptom was the rad fan on most of the time...............................
(and going into the red once)