Well, this may be true for the older browsers but not Mozilla 3.0 and up. But then again a spider is nothing more than a stripped down browser which makes me think there might be a SE advantage in some cases (not all). I hear from others that Lycos and Excite prefer dedicated IP's.
Other Advantages
[ie-host.com...] (not my host)
Not sure what you mean about the path to the site but the domain name and IP address are both resolvable.
>>>Dedicated IP's are going to be more and more scarce as more hosts go to name based domains<<<
Actually, they are running out of IP numbers.