Hi, Don.

DNS lookup speed is part of the overall page load time and reducing it may or may not be noticable - depending on how fast your current DNS servers are providing DNS information. If your ISP is providing DNS for you and it's working the way it's supposed to, then any DNS lookup shouldn't be adding much time to any page load.

Each DNS lookup only needs to be done once, so on a normal page with data from only a couple different domains, the DNS server isn't going to be much of an impact, unless it's really slow *or* there are a ton of DNS lookups to do on the same page (like on Myspace or somewhere that's bringing together data from a lot of different sources).

PingPlotter really doesn't do much for you with DNS testing because any lookup is going to be cached at the server (and your computer) so doing repeated lookups of the same data (which is what PingPlotter is so good at) isn't really the right way to test unless you're only interested in the network part of the DNS lookup.

The latest beta of PingPlotter does do UDP DNS testing, but it focuses just on the network component of DNS, and not the whole DNS process.

I'd probably look for a tool that is built for DNS performance testing (like the one here: http://www.georgebreese.com/net/software )and see if your servers are performing well or not. I've never used this type of tool, but it looks promising.

Good luck!
Pete