One of the best things about Rackspace, and probably the one thing that they champion internally is their support. Getting someone on the phone is super easy. Each time I've called, I've gotten someone that is US based, has a personality, and is intelligent about what you need help with. Their product offering is geared towards advanced power users (sys admins, engineering types) and they provide support with people who are competent in that area.
Not only are they responsive via phone, but also via chat, and their ticket system. If you need support, Rackspace will provide it. Their pricing isn't the cheapest, but it's not the most expensive either. It's a great value, and if support is important to you, you needn't bother looking any further for a cloud infrastructure provider.
Their stability is great, even when the hypervisor scares in late 2014/early 2015 came about with bugs that allowed attackers to break out of their virtual machine, they were responsive and orchestrated a huge upgrade across all their infrastructure. They achieved it in such a way that allowed us to avoid down time, despite our host machines needing to be rebooted. When they applied a second patch that required reboot later that year, they were able to achieve it without us having to do anything because they automatically migrated our virtual machines to different hosts.
I can't say enough about how great Rackspace is. They treat their customers with respect, and it's evident in the amount of effort they put into supporting them. I would definitely recommend utilizing them if you're in the market for cloud based server infrastructure.
Review collected by and hosted on G2.com.