I also loved the Meseta. And I was hardly alone. It was a regular topic of discussion among pilgrims -- "How can people say this is boring?" It is beautiful.
And don't let anybody kid you. It is not flat! No, it's not the Pyrenees. But it's definitely not flat. (You want flat? Come see Delaware!
).
I loved the rolling hillsides, and the villages tucked in the valleys that seemed to materialize out of nowhere. In April there were a thousand birds singing every morning, and the fields were a dozen shades of green, and the sky, brilliant, cloudless blue.
And mystical. Any regular reader of this forum will know three names that come up repeatedly as very special places on the Camino-- San Anton, San Bol, San Nicholás. All on the meseta. Connection? Think about it.
Shortly before Sahagun there is a slight alternate route to the hermitage of the Virgin of the Bridge. Just beyond that are statues and markers declaring you are crossing the halfway point between Roncesvalles and Santiago. You can impress your friends with a certificate to that effect from church museum up the hill as you leave town.
There were many bicyclers. I don't know the rental companies, but there seemed to be plenty. And, contrary to many reports I have read, my experience was that they rode at a moderate speed, alerted walkers they were approaching, and, almost without exception, wished us Buen Camino or Hola as they passed. They looked like they were having lots of fun.
Enjoy the Meseta. It's very special. Buen Camino.