If you find yourself on Rackspace hosting I would absolutely migrate to something more mature. Personally I've had great luck with Digital Ocean and Linode for basic/affordable VPS hosting, with AWS being a great cloud provider with an incredible tool-box at your disposal. Hell, GPC, Azure... there's just so many better options.
IMO Rackspace has been on a steady decline for years. They were a choice provider back in the early 2000's when a managed/unmanaged beige box/shared cPanel/Plesk hosting was common. Back then their support was incredible. Sometime around 2010 though things started to go down hill, and I experienced more and more support issues with them. These would range from annoying all the way to "that shouldn't happen" (like losing volumes, which happened to me).
The final straw was when a dedicated server was turned down by mistake, causing a major outage for 20+ of my clients at the time. This was 10 years ago and I've never looked back. They did a pretty good job at turning me into an advocate against their services.
Oh and the Slicehost transition was crap too. That sucked to get over to a first-gen VPS provider only to have it sucked right back into the beast that you were trying to escape from in the first place...
Sorry for the mini rant. I'm still not over the PTSD that Rackspace has caused me.