In terms of size. Sizeeasy is a fantastic tool, allows you to place objects side by side and see how they stack up, size wise. Engadget and Gizmodo use this tool often too. This is what i've put together:
I'm surprised to find out that the Vox is pretty small, not quite as slim as the Excalibur, but definitely smaller than the Hermes. Perhaps closer to the Artemis which is a nice size. Can't wait!