Wondering how the op made out. Older thread but was considering a 4 day stay myself in Glasgow
If you have 4 days i would go to Edinburgh.
Why discourage from Glasgow? It has sooooo much to offer and yes I am from there and slightly bias :) I have always felt that the capital is pretty and has the Castle but lacks feeling maybe due to so many toursist being in it.
get a huge discount on Glasgow Hilton
is 4 days enough to see both cities and maybe head up to the highlands?
Yes you can get to Edinburgh in about an hour, might push to do the highlands, but out of Glasgow within a short time frame there are some beautiful places to visit.