Megabus is a bus company that tries to minimize their costs in order to minimize their prices. Whereas some 3 or 4 years ago their prices were truly amazing, right now I do struggle to buy tickets in very attractive prices if not booking weeks ahead. The buses are usually clean and in good condition, out of my numerous travels with them there has been only one occurance that they were late more than 1 hour. The elaborate system of transfers in order to get for example from Aberdeen to Edinburgh Airport does not make it simple and comfortable as it could be. Moreover the wireless that is advertised on their buses a lot of the time does not work. Overall, it is value for price and most of the time cheapest option to get south from Aberdeen, nevertheless, if you have money you will be more comfortable taking the train, and it will save you time.