Hopefully, you get someone who has been in the area to give you better detail (I know of at least two TE-ers who have been to Tuscany). We were in Tuscany briefly before heading east into Umbria and Marche.
As a flatlander, I can say this much...I preferred the hills that were 7-10% and long over the shorter 10-20%-ers. In the area, most of the time "long" meant no more than a mile of climbing--the area was more rollers than mountains.
One day we had almost 20 miles of up, some of it was steeper than 10%, but, quite frankly, that was easier. The reasoning is that when the climb continues, you enter a climbing mindset and you just go. You're not looking for the top and panic-ing because it is "so far away"; instead you find the easiest gear and just keep plodding. I found I saw a lot more of the scenery on the longer climbs.
Good luck. Enjoy the views when you get to the top!