Nice report! The wife and I just did a trip to Scotland this past May/June. We rode in the highlands. I was most impressed with the quality of the roads. The weather and having to drive on the left were the only issues. Breathtaking scenery, though. Still reliving it through all the pics we took.
In 2006, we really enjoyed the highlands via motorcycle (Honda Deauville 650 that time). It was the 2nd half of June, but the weather was amazingly unusual... only rained about 2 hours around Fort William. Most of that trip up from the south of Germany to Inverness, Scotland and back was dry (while we were enjoying 70F sunny days in Scotland, Wimbledon tennis tournaments were getting heavy downpours in England that year). The Lake District of England reminded me of the lakes we passed in Scotland that 2006 trip (Loch Lomond, Loch Ness, Loch Tay...), but nothing can compare to the the ruggedness and more spread-out landscape of Scotland.