Part of the reason that such mittens are so wonderful is the Shetland wool that they're traditionally made from. Shetland has a reputation for felting if you so much as look at it crossly, but this allows the stranding to hold together and will eventually cause the gloves to felt in the shape of the wearer's hands. The Shetland used for these particular gloves was the wonderful Jamieson's Shetland Spindrift.
Dare I say that my favorite part of working with this yarn is how beautifully it spit splices? Spit splicing my preferred joining technique when the yarn allows it. It leaves no tails to weave in and makes me feel like I'm doing a little magic with only my saliva (or water, if that's the way you roll). Spit splicing is right next to turning a heel on my knitting favorites list, it's just that magical.
While there is something incredible about fair-isle gloves, they really are a lot of work. These gloves for example, which are pattern Annemor #8 from the aforementioned Selbuvotter book, where quite fiddly in the the fingers. All this leads me to the conclusion that I'm not going to become a die-hard fair-isle knitter, but I won't say no to future fair isle projects either--as long as they are mittens and not gloves.