I reckon they've got more carts in Edinburgh than Glasgow. I've seen them at Waverley station, Charlotte Square, the Royal Mile, Nicholson Street and Bruntsfield.
In Glasgow I've only ever seen them on Great Western Road next to Oran Mor and under the cavernous highland man's umbrella at the central station.
I think they're reducing here: they've disappeared from Middle Meadow Walk and the roof of the Waverley Market, rare at the West End, sporadic on the Royal Mile and on St Andrew Sq: I've spent the last 2 days working on the latter and watched the JWs and the carts and there was zero interaction with the public. It looks mind numbing but at least they've topped up their tans this week.