I have been wearing VFFs since 2008 and have loved them ever since I first tried them on. I use them for everything and only wear regular shoes on special occasions like a fancy party that is too fancy for my leather KSO Treks.
As was said above take it slow... the first week wear them all the time but only walk. If you have to run throw your old shoes on. week two go for a short jog in them and so on. It should take about a month to work up to wearing them full time. And about 6 months before you can wear them all day everywhere and not have sore feet/calves at the end of the day. There are lots of resources online, here are a few I like:Running in Vibram FiveFingers: A Step-By-Step GuideWelcome to Vibram Five Fingers - YouTube
I have 4 pairs of various VFFs and my original pair are still in good working condition. They have lasted quite well. My KomodoSport VFFs are my favorite for Parkour but the KSOs work well too. I have found my KSO Treks tend to slip on pavement and i only use them when running dirt trails or out in the woods. Your choice on the Flows will be good for the up coming winter months.
Pro-Tip: Invest in Toe Socks. Injinji Toesocks
If you have any more questions feel to ask