I fitted some "Amazing special" things that cost about £20 a set, they luckily align with the "spare" handle bar mirror tapped hole on the master cylinders. But I had to nick the bar weights off my VFR Vtec which are about 1/4 inch longer to get the end cover to expand enough to clear the clutch lever.
I ride to the centre of London and back every day, about 84 miles each way and even at -5 last week, with these on and the heated grips set at 3, plus my heated KEIS vest and the usual Dianese over suit I was more than warm enough, could have done with some lip balm maybe, but as has been said, it's about clothing for the occasion. Normally cruise at 6,000 rpm. (although the rev counter might be out a bit?) I also get 55mpg at that speed, not that mpg matters, I run a Jaguar S type 4.0 as well, don't worry too much about the cost of fuel after a week in that... I do confess I need a "comfort break" at about 60 miles, but I do drink too much before I set out at 05:00 every morning...
Pretty sure the deflectors do a good job of keeping the cold off the back of my gloves though, heated grips are fine for the palm, don't do anything for the icy wind running over the back of your hand, and for a 61 year old I guess I have pretty good circulation because all I ever get is a loss of feeling to my index finger after about 60 miles. Occasional cold feet too, but has to be wet as well as cold for that to happen.
Yes, can thoroughly recommend some kind of wind deflector "bark Buster" type fitting.
My biggest problem is that because I ride a bike every day, it's not such a "weekend toy" any more.
In fact I just replaced the standard rear shock with a Maxton unit because the standard fit thing was losing it's ability to keep me and the seat connected quite rapidly. I was getting quite a lot of "traction control" activation and I don't ride with a "Today I might die" type of style. 20,000 miles... Next will be the forks I think.