Not given any thought as to why the difference occurs however bleeding the system in my instance has made no difference. It must be due to the lever. Whether a firmer feel with DP aftermarket levers wound in is possible, I'm not sure. The lever always did feel rather soft however I believed it had become considerably softer over the winter hibernation. I had wound the lever out previously during the brake bleed process and assumed the increased firmness was the result. Winding the lever back in to ride the bike I had initially thought I had introduced air into the system during each brake bleed. It was only at the weekend following a further needless brake bleed that I kept the lever wound out during the ride and discovered the difference. I then found this thread. I prefer the soft lever but became convinced it was becoming too soft. I'll persevere with it and see what happens. During each brake bleed there was barely any air in the system (if any at all) and so my initial thought was that something was failing.
I run a close lever on the road, and wind it as far as I dare out on track. Its the balance of feel vs bite Probably something to do with fulcrums, or falcons, or eagles...