Scotland is amazing. Of the places I've visited, it's the one that I always want to get back to. Other places are "Been there, done that", but Scotland is special for me, and I've not explored nearly as much as I'd like to. As far as the weather goes, I went to Scotland last year on summer solstice just to see how far north I could get without making a major effort. (I was living in London at the time.) I was a bit bummed to have a very overcast day in Inverness until I realized that the scenery is majestic even with the clouds hanging down into the hills. Sunny days (and yes, I've been there for some) provide amazing blue skies. OP's comparison points suggest that the Highlands are probably the target destination, but certainly don't overlook Edinburgh (despite loving London after 22 months there, I think Edinburgh really has my heart) and St. Andrews. The ruins of St. Andrews Cathedral are amazing, and my visits to Scotland taught me much about the Reformation that my Lutheran upbringing left out.