Doing a little reading, it appears to be a common problem, and I decided to get get a saddle with lots of middle relief - basically a saddle with a big hole, or channel, in the middle.
Shipping around I short listed it down to the Specialized Evo Pro and the Selle Italia SLR Superflow.
The Spesh is marginally lighter (173g vs approx 200) and gets great reviews, but has carbon rails that meant I'd need a new seat clamp.
5 minutes on eBay and I was the proud soon-to-be owner of a super-light eXotic carbon seat post, and a couple of days later a new Specialized Evo Pro from Sigma/Specialized Concept Store in Kingston.
Fitting underway and reports of (hopefully) improved comfort to follow!
The new Specialized Evo Pro... fingers crossed!
My aging WTB Laser V
The Felt saddle