Basic tracks for 49 songs in ten days really isn't that surprising with a band that's spent so much time together and plays live without a "take two" several nights a week. They had time to learn the material, rehearse, and then come into the studio and lay it down. That just seems to be the way Carlos likes to work now. Studio time for a band like Santana is still expensive and album sales are for shit no matter how well it charts thanks to file sharing and streaming services, so it's not surprising there'd be a premium put on productivity. Supernatural came out at basically the end of the era where a strong record could be a consistent seller for months. Now you get the majority of your sales in the first week.