As various armed forces around the world have learned, light grey paint on something makes it blend in to the skyline. Which is why fighter planes and warships are light grey. The same principle can be used on wind turbine and it makes them less noticeable from even surprisingly short distances.
The size of a turbine can have an impact and when it comes to fitting sympathetically with the landscape, big is better. The larger the wind turbines the greater the energy produced. So for a wind farm, increasing the size gives you more energy with fewer wind turbines. Several larger turbines may be far, far less troublesome than more smaller turbines. This is in addition to any economic advantages from things like lower maintenance costs.
The aesthetic aspect of large wind turbines is slightly more technical and involves the way the brain sees things. A larger turbine will, generally speaking, rotate at a slower speed than a smaller turbine. Because of this slower speed, the larger turbines do not catch the eye, in the way that a fast moving turbine would. Also, in a rural setting the slower, seemingly lazy movement of a larger turbine can be felt to be more suitable.
To a (probably unsurprisingly) large extent, it is more down to personal taste as to whether people perceive that a wind turbines fits into the surrounding landscape.
Numerous studies have been carried out in the UK, Denmark, Germany and the Netherlands which have shown that populations in rural areas surrounding wind turbines are, on average, much more favourably disposed to them than city dwellers.