Pamplona - Burgos

There is much more happening between Pamplona and Burgos than there is between Burgos and Leon. More towns, more varied countryside, more hills, etc. Of the two I would choose Pamplona to Burgos.

The meseta between Burgos and Leon will give you a chance to walk without too many distractions. If it's places to see and nature you are looking for then Pamplona to Burgos seems the choice for you.

Your choice need not be either or. If you only have two or three weeks you could start at Roncesvalles (attend the wonderful 1000 year-old pilgrims' mass) and walk for a week or so, then get a bus to about O Cebreiro and walk the last 10 days.