i been with lunarpages for about a week now and havent noticed anything bad, very smooth moving over
only needed support just after i signed up to change my main domian on my account and this was done quickly
havent noticed any speed issues here in the uk, but im only on 500k dsl so the connection is easier to fill, although my page loads in a flash. at writing its taking about 1-2 seconds to log into ftp and ping is 168ms. although it is 4.30am here and quiet traffic wise
HostPulse.Net has a ping time tester [http://www.hostpulse.com/app/networktools/ping.asp], however the ping isn't going to tell the true speed of a host. If a host has a file you can download, you can try out that and you can see how fast their network is to you. Keep in mind though, while it may be fast for you, it could be very slow for someone else living in another part of the country.
Also it doesn't matter how the network is, if the server is a Pentium 1 75 mhz.
Thats is a good ping time buoy. And those results is just from that test site. Wich might be very favorable to the hosting company at that location. Obviously the closer you get to the end network, the better the latency.
Anyhow, dont search for a host using the ping or latency time argument. It really does not show anything about the performance of the company as latency or ping is not that relevant to webhosting anyway.