I agree a separate monitor is required to make it a primary computer. Additionally, I bought the macbook 13" for the exact same reasons as you both mention but the size argument fails soon after you realize the macbook is not that small. It only weighs one pound less than the MBP. If the extra screen size is too much for you to fit in your bag their might be something else wrong with you.
trolling, trolling, trolling...how long must you keep this up...