I'll echo this--we moved nearly 100 sites off of Rackspace over the past year. All the Wordpress sites went to WP Engine, and the Drupal sites to Pantheon.
For years, Rackspace provided amazing sysadmin support, but there was always a gap between where their support ended, and the best practices for WP and Drupal sites began. That included tuning the LAMP stack for those applications, configuring dev sites and deployment processes, and managing caching and TLS. Rackspace helped with general advice, but we had to "do" it, and maintain it.
That's not true on CMS-specific hosting like WP Engine and Pantheon; it's all in one package: production hosting with scaling, dev and staging sites with one-click sync and deployments, CDN, TLS certs via Let's Encrypt, and support. We went from spending almost an FTE's worth of time on sysadmin and dev ops, to almost no time on those things.
I'd say I wish we had done it earlier, but in my opinion, we could not have. It has only been within the last year or two that these services have really put together the full feature set we wanted.
For years, Rackspace provided amazing sysadmin support, but there was always a gap between where their support ended, and the best practices for WP and Drupal sites began. That included tuning the LAMP stack for those applications, configuring dev sites and deployment processes, and managing caching and TLS. Rackspace helped with general advice, but we had to "do" it, and maintain it.
That's not true on CMS-specific hosting like WP Engine and Pantheon; it's all in one package: production hosting with scaling, dev and staging sites with one-click sync and deployments, CDN, TLS certs via Let's Encrypt, and support. We went from spending almost an FTE's worth of time on sysadmin and dev ops, to almost no time on those things.
I'd say I wish we had done it earlier, but in my opinion, we could not have. It has only been within the last year or two that these services have really put together the full feature set we wanted.