Apex- I used to be a snowmobiler. We would ride down to -20f, including late at night. We never used heated gloves, just heated grips and they always warmed our hands. I use a pair of Ski-Doo brand snowmobile gloves on the colder days because they are thick and well insulated with a nice long cuff to go over the jacket sleeve; but the palms are thinner so the grip heat will pass through, and the gloves aren't bulky feeling.
Oxford grip review after using them a few weeks- The controller has to go. It is as clumsy to use as the Honda one. Its unlit when off, and when on only has a small LED showing the heat setting, but no light to be able to see the buttons. The LED can only be seen if the switch is positioned just right, and not at an angle. The buttons are too small to be able to feel them with gloves on, so there really should be some kind of illumination for the switch pad.
Grips- These specifically are listed as fitting an ST1300, but they are almost 1/4" narrower than the Honda grips, so there is a gap between the grips and the bar end weights. This makes them feel narrow, and to compound that, the grips have a fairly large ridge at the end of the grips, making them feel even narrower. With my large hands I felt cramped when wearing gloves. I ended up carefully cutting the ridge down to the diameter of the grips so I have more room. They are comfortable when using them now.
Function- They work very well. Other than the clumsy switch pad, they are great. They get very warm- on most cool days I only put them on the 2nd to lowest setting. I have only used High when first warming up the grips (they warm pretty quickly) and for a few brief spells on very cold nights. Out of 4 positions, I usually use #2 or #3. They seem to warm very evenly between the left and right grips. This is one reason I decided to go with these over the heating elements you can buy to use with other grips- these have insulation between the heating element and the bar. With my KLR I used two different brands of grip heaters (element pad style) and with both, the right one would work very well, and the left much less efficiently, because the right side is against the plastic throttle, and the left is directly on the metal bar which acts as a heat sink. I tried wrapping the left bar to insulate it which only improved it a little. But the Oxford grips are great, and are very even.
In looking at the different models, I think I would need the ones designed for the Gold Wing to eliminate the gap. I am also planning to upgrade to a rotary switch at some point to eliminate the clumsy switch panel.