In reply to Roberttaylor:
I don't think that it'll take much longer going by Aberdeen - driving back up from Glasgow it sometimes takes longer going via Braemar by enough of a margin you could be to Ballater in the time comfortably.
As alternative to other suggestions you could walk in from Balmoral and via the geldershiel bothy to the NE corrie.
Takes longer that from Glenmuick but definitely accessible by public transport. you'd have to walk over the top to get to Dubhloch though.