I have a selection of both Tom Bihn and Red Oxx carry-on bags. Much of the distinction between them comes down to subjectivity and personal preference. For business and leisure travel on short flights, I find the organisation and aesthetic of the Tom Bihn Aeronaught 30/45 and the Synik 30 difficult to beat. They are practical, brilliantly well designed and a pleasure to use. The Red Oxx Air Boss and Sky Train do not have the same level of organisation, but they are indestructible, and my wife and I found them invaluable on safaris in South Africa and Botswana, and island-hopping around Mozambique. They all fit in the varied luggage compartments of small planes, and can handle rough treatment and being thrown in and out of jeeps. Both makes are great - I always use packing cubes to simplify organisation (but I am OCD....)