Had a VPS with SLHost.com for a month. In that time their service was nothing but excellent. I'll post what you'd want to hear if you're in the market.
1) Setup Time - Spoke back and forth with one of their site admins who post on this forum prior to ordering. Said they could setup within 2hr this was late night between 10-11 EST. Was actually setup within 30-45 minutes. Impressive.
2) Uptime - Other then when I stopped httpd site was always online.
3) Staff - I put that in bold because with some companies they have great staff and then terrible unknowledable staff. Read the italics below for more info. SLHost has excellent staff who are very knowledgeable. I'm pretty familiar with server administration, but in the few times I was stumped they were able to assist promptly. Also they took the time to point out the cause of the issue which will help should the problem come up again during another server configuration / addon install.
4) Response Time - Ticket response time for me was around 10 minutes or so. Maybe a little more. I usually contacted late night so once again this was impressive.
5) Live Chat - Live Chat was actually able to do something other then tell me to email sales@ or email support@. That was shocking. This was around the time they introduced the new plans with double space, etc.. Was able to get upgraded to that through Live Chat and Also order some IPs on a different occassion.
6) Management - By fully managed they do include full management. Some companies offer basic support, etc.. but leave you stuck with other issues. I got the same level of support as if I was on a shared hosting account which was suprising.
7) CPU, etc.. - These are VPS machines so really they way you have httpd / mysql, etc.. configured will affect performance, but I got every bit of what I paid for. Everything that was guaranteed was there. No complaints here.
Overall as you can see I was very happy with SLHost. I did cancel although it was a hard decision. Only reason I cancelled is because as I said previously I am pretty good with server admin, I launched another high traffic / cpu / mem usage site so an unmanaged dedicated server was a better option for me. They do also offer dedicated server options. I had overlooked that at the time or would've inquired with them.
If you are looking for a VPS I would say they are a great choice.
**3** I had a prior VPS with a different company prior to using SLHost and they had TERRIBLE staff who were by no means Support. That company had some great staff as well though. I cancelled furious at the terrible support and signed up with SLHost. I won't say the other companies name because despite the bad there are several great people that work for them.