Enjoy your F10. I have had my D30 for a few weeks now (I also love it) and am just at the point where I want to start playing with the power levels. I rarely use level 3 so I think I will currently leave it at 100% and use it as a desperate 'get out' if I become too tired to cycle, or the hills are too steep. I think I will also leave level 1 at 100% as that seems to suit me at the moment, but I may change that as my fitness returns. Level 2 is where I will reduce it I think. I find it too powerful, meaning that I hardly have to work, except on the steeper hills. I think I might try setting it at 75% then experimenting from there.
It might be worth reading back over the past 5 or 6 pages as a few of the guys on here are really knowledgeable and very helpful. They have played around with the settings quite a bit and I am fairly sure there are some pretty recent posts on their preferred settings. They will be much more helpful than I can be!