In reply to balmybaldwin:
"The bruising of your bones will stop quite quickly if you ride it at all often, and you will then find it more comfy over long distances due to the lack of chaffing that the heavy padded saddle would give you."
Both are almost identical in volume, size and shape. Just underneath one is just plastic and the old one is plastic but much lower type thing with padding between. So in theory it should be easy to adjust from one to the other. However the reality is I went for a 20 mile jaunt the other day and it was brutal, never stood up so much on a ride before!
Think I might put it on my commuting bike which I use much less but much more regularly (4 miles a day on avg.)