The Isabelline was definitely present later than 15:00 - as I left several birders watching it at c.15:15. The bird was giving excellent views, albeit in poor light conditions, but had relocated to a field some 150-200m up the road (towards St Justinian's) from the car park at Porthclais. This field is on the left of the road - just before the brow of the hill above the car park.
Elsewhere today (and yesterday) - as David says - it was pretty hard work. The valley at St Govan's head had a single Chiffchaff (briefly) and a male Blackcap today, a slight improvement on the female Blackcap that was there yesterday. Plenty of Goldcrests around the house at Orielton today, along with a male Blackcap and a Chffchaff - but otherwise very quiet.