I am mentally cycling to work to try and come up with something.
Melville Drive lanes (during hours of operation) are great, allowing you to sail past the daily queue of traffic (could do with a feeder lane from Marchmont Road immhoo).
It's useful and saves a good mile and a half being able to cut past South Gyle railway station to get from Corstorphine to Gyle estate, although it's not been done in a very clever way (coming on the road you have to catch the lights and cycle onto the Toucan, bump through overly bumpy speedbumps past the school then bump across badly dropped kerbs outside station with badly located bollards, on a rather blind (but thankfully quite quiet) bend. Actually, scratch that, it's useful in spite of any efforts to make it cycle-friendly, not because of it!