Early To mid May, Mr MacMidge is still hibernating up there. August is a no no, they will bite anything that moves, but the Avon skin so soft, does help immensely. I have been up there, sadly not on the Loch, different times of the year.
September is the joys IF the weather is kind, the colours are stunning, and the midges have had their fill for the season.
Yes, it's very expensive up there, but, you just don't get scenery like that every day, IMHO.
Iain