A real user!
I used the Caledonian Canal for its intended purpose last April - I brought my boat through when taking it from the Clyde to a marina near Walton on the Naze. The complete passage from the Clyde to Walton was a bit of an epic ; we took 3 weeks (including rest days and the days when we decided the weather forecast was too bad!). We didn't use the other scenic canal - the Crinan Canal, while a very pleasant and scenic route is ridiculously expensive for what you get. Also, from most of the Clyde, it doesn't give a time advantage, so we went round the Mull of Kintyre.
The Caledonian Canal was very interesting, and we spent nearly a week on its waters, entering at Corpach and leaving at Clachnaharry, where the Clachnaharry Inn provides an excellent pint and a decent meal. Going up and down the staircases of locks was awe-inspiring, and even a little vertigo inducing when looking down a flight from the top! As a user of the canal, the only real inconvenience was that movement on the canal is prohibited after about 5.30 pm, and the last obstacle (the swing bridge carrying the road below the Muirtown locks) can't be used for about 2 hours before the canal shuts down for the night because rush hour traffic takes priority. Sadly the mooring above the Muirtown locks doesn't have much in the way of facilities, and at that time of the year we valued the availability of mains electricity!