Seems to be setting up in competition with Edinburgh - the weekend before (assuming Edinburgh falls on the same weekend as this year) and the same price.
330 - there are more than you think. I've done a wee trawl and found all these......
Glentress (trail) - February Meadows (Edinburgh) - March Edinburgh - May Cape Wrath - May Strathearn - June Dundee - July St Magnus, Orkney - July Fort William - July Glasgow - August Loch Ness - September Moray - September Islay - September Glencoe - October Rannoch - October
This thread is from 2008, and I'm pretty sure I've read that they have changed the way they harvest the stem cells, so it's much less invasive and no longer painful, other than a few needle jabs. They used to actually remove marrow from the inside of the bones, now it's pretty much like giving blood.
Well done you for donating. I've been on the register for many years, but never had the call.
Might be an idea to go out for a long walk over the next couple of weekends (or whenever you have the time available) to get used to spending a lot of time on your feet. Maybe walk for 2.5 hours with some running bits thrown in. At least then it won't be a huge shock to your system on the day.
If you can run 7k, you are fit enough to walk a half marathon, so you will get round.