The Pro 3's are currently on price drop on
Wiggle and can be had for very little money at the moment, circa £17 each.
They came as OEM on my bike and despite having two boxed and unused 4000s in the garage I have stuck with them and have no complaints.
When the time comes to change them the currently plan is for some Pro 4 comps, which are a little lighter. They are just blooming expensive and no one is doing any deals on them currently.
All that said, I loved the 4000 S when I switched to them and currently run them on my wet weather / winter bike.
Now trying to work out if I ought to keep the two new and boxed 4000 S as stock or just flog them and put it towards the Pro 4 Comps