I recently received a Sony 24-104 f4 lens and I love it. This lens is so versatile. I can see this as my main travel lens. On most trips I will still take the Sony 16-35 f2.8 GM for landscapes. Smaller international airlines have a 8KG carry on luggage limit. That means a maximum of three lenses so selection is very important.
Don't just take my word for it. The reviews for this lens are really outstanding. Some are even saying go with this lens over the 24-70 f2.8 GM. Much cheaper and lighter.