Boots or shoes?

One debate that I've had going on for awhile is whether to wear boots or shoes.

I'm getting different opinions on this depending on the background where people come from.

Boots - suggest by MRT member that they reduce the risk of injury and if I did do over on my ankle, more likely that I would have less problems continuing.

Shoes - because of my background in fellrunning and relative lack of ankle injuries over the years (in 25 years, two sustained whilst running and one while not), I should have natural strength in my ankles which boots would reduce, therefore causing more problems than they solve.

I currently walk in either Columbia Pinas which I bought in the States a few years ago as an emergency purchase (ok for the odd walk) or Karrimoor Pyramid Wethertite shoes which I bought for winter walking when I didn't want to wear boots. I'm not convinced that they are suitable for 50 days walking of up to 10 hours a day. I also have a pair of cheapish (£40) Hi-Tec Knysna Mid boots which were fine for my 20 mile fast walk over Helvellyn and Thornthwaite Crag at Easter.
I'd obviously welcome any comments gained from experience. I'll also post in relevant forums. Some people have even suggested that I wear trail running shoes such as some of the Inov8 range (I usually wear mudclaw 330s for fellracing).