The Lonely Planet has just name The highlands and Islands of Scotland as one of the best top ten holiday destination. It talks about the route 500.and 250 the scenery and natural beauty.
Whilst you can not argue against this article, you need to remember that the advertising for the route 500 has made this area busy, you need to make sure you have booked accommodation in advance and know where the refreshment places are.

The Southern Highlands and Islands are just as stunning and off the ‘beaten track’

Whatever you do don’t look at the map and think ‘we’ve only got 80 miles to drive today, we’ll have loads of time’.River Add looking over towards Mull

The roads are slow and difficult to navigate and you’ll inevitably get stuck behind a RV, caravan or two. Once you factor in endless stops for unmissable photos, side-trips to museums, beaches and a wee hike, time for lunch, a little tea break by the roadside and spontaneous detours to places you see signposted off the route, it will be 7 p.m. before you know it and you’ll only have driven 60 miles!
https://www.bbc.co.uk/news/uk-scotland-highlands-islands-45940644#_=_