Hello senseamp, there are a lot of us here who are of the same opinion (black thoughts of blood clots and death), and yes, that's why some of us are here.
You might do well to ask the folks at the Clydesdale forum about their experiences...
http://www.bikeforums.net/forumdisplay.php?f=248
They are the experts!
Welcome back to cycling, and welcome to BF!
Where are you from in England?
East Hill