I'll start off this review by saying that I'm not VPS/Linux/Dedicated Server/Server Doohickey expert, but this is what I've found for Fliphost, with my dedicated server:
Support
I need to start off by saying the support at Fliphost is phenomenal. I've never had to wait any more than 30 minutes for a ticket response, and quite a few times I've had responses in under 10 minutes, which is faster than most providers. They are very knowledgable about what they do, and they take pride in it.
Network
I've tested pings from around the US on their network, and for the most part it is very good. There are a few quirks (Some odd pings to st louis and western canada, but those seem to happen to more than 1 provider). The upload/download speed is what it should be for my uplink (100Mbps and ~11-12 MBs upload/download). The uptime is also very good, and is basically the same as what they promised on their website if not better.
Server hardware
I personally got the Dedicated 101 package that was offered on lowendbox.com a while ago because they still had a deal running on it. The server has been performing very well for it's price point and I'm very happy with it, everything is correct and it functions accordingly (no malfunctions I've seen as of yet)
Conclusion
Assuming they still have the promotion going on, Fliphost thus far has done a very good job of assuring that their customers are happy, that their network is running without issue, and that the servers they run are running fine.
I'll update this post if any of this ever changes. Also, this is my personal experience with them. It's not a guarantee that yours will be the same, but they have been a good host thus far to me.