I've been using them for years and currently have 39 domains with them. Their control panel is easy to use. The didn't used to have auto renewal which was really annoying but they finally added it last year.
I strongly recommend against using registrar DNS hosting. Most registrars offer DNS as a value added service and don't put any effort into making it fast. I've seen GoDaddy's DNS servers take hundreds of ms to respond. I've not tested Namecheap's servers. If you want something free use CloudFlare. If you want something cheap use Route 53. Both are good, fast services and are far superior to what you'll get from a registrar.
I strongly recommend against using registrar DNS hosting. Most registrars offer DNS as a value added service and don't put any effort into making it fast. I've seen GoDaddy's DNS servers take hundreds of ms to respond. I've not tested Namecheap's servers. If you want something free use CloudFlare. If you want something cheap use Route 53. Both are good, fast services and are far superior to what you'll get from a registrar.