I've used A Small Orange, Slice Host, and Linode in the past for VPS and cloud based hosting, and I've been happy with Linode, so I was taking a look at Savvis Direct for a new project.
Some things I saw from their unmanaged cloud options.
1) They don't give you many OS options: CenOS (32 and 64bit), Ubuntu, Windows 2008, Debian v6. But that doesn't bother me too much.
2) Looks like they only have US based datacenters, 2 in Virginia, and 2 in California.
3) They don't provide a point in time/backup option to their cloud storage.
4) I can't find anything about their DNS configuration or setup.
5) They don't give you much disk space compared to other plans.
Price-wise, when I compare, I usually look at a company's product with 1GB of RAM, and in this case, for about $70 and a linux OS, you get 1 CPU Core, 1G RAM, 75G outbound bandwidth (unlimited inbound bandwidth), 10G local storage, 10g cloud storage.
For almost the same configuration on Rackspace, you'd get more diskspace, depending on your bandwidth used, because Rackspace bills their bandwidth separately. If you don't use much bandwidth, Rackspace would definitely be cheaper.
You get a lot more bandwith and storage for less USD with Linode, but that's comparing the "cloud" to a VPS, and I don't think you can guarantee yourself a full CPU core on Linode. Linode offers a few different options for backups, which I like, and their interface is pretty good.
So, I don't see anything for me in Savvis Direct that would entice me to switch from any existing provider. Anybody else?