Beyond ip security and Nessus

The representative of this company :

www.beyondip.com/pages/Support/support.htm

has stated the device of this company has no impact on any network device during its vulnerabilities scan, though if it is peak time.

Any insight ?

If we want to do comparison between it and Nessus

The device as representative mentioned it is a special dell box compatible with the specific Linux OS designed for this purpose (vulnerabilities scan).

What are they going to charge you to do this? If the cost is ridic. and you have a little experience in bangin out code than might I recomend "Nessus, Snort & Power Tools" published by Syngress. With a little time and effort you could set up something comparable to what they are offering.