Microsoft Surface Pro 3 or Yoga 3 Pro

Why
Light (up to 1.2 kg laptop) that you can also use as a laptop.

Good of both
- Pretty design
- Fast start

Pros of Surface 3 Pro
- Removable keyboard
- Really usable as tablet (Yoga 3 Pro is heavy as a tablet)
- Accesories are widely available

Pros of Yoga 3 Pro (vs. Surface 3 Pro)
- Bigger screen
- More USB connection
- Cheaper
- Perhaps better screen
- Cheaper
- Larger hard disk (Surface 3 Pro has 512 GB one, but it is the most expensive one)

Decision
For really daily mobile use is Surface 3 Pro better. If the budget is limited, Yoga 3 Pro is a superb alternative.