An iPad Pro + Bluetooth Keyboard weights more than the Macbook 12". It is even more clunky.
With Apple's new Bluetooth keyboard, it doesn't feel clunky at all. I haven't checked the exact weight of the Bluetooth keyboard vs the retina MacBook, but carrying the iPad Pro plus the keyboard isn't a problem at all for me. The combination feels really light and easy to carry. I've been moving from room to room all week, toting my iPP and the keyboard. I also find that being able to position the keyboard and screen separately is great. I can put the iPad at a comfortable height for me to see the screen and type with the keyboard on my lap. To me, this feels more comfortable than typing on a MacBook, or any of the various keyboard covers for iPads, Surfaces and similar devices. I understand that other people might need a mouse/trackpad to do their work efficiently, but for my job, I don't need a mouse, so the iPP is a great productivity tool FOR ME. As I've said a few times already, I still need my desktop, but I don't foresee myself buying another laptop.