I don't know that I really think this guys methodologies are all that valid... P3-800 with 256MB of RAM and XP-SP2?
Wouldn't such a system just sit there and swap even without anything loaded?
Surely if IE loads any componants at startup, as I believe is the general consensus, that would give it an exagerated advantage on such a system since it is already in memory when any other browser starts and must be swapped out first.
Even if that's not a consideration I just don't think that a setup like that would really reflect the performance most users could expect. Clearly memory and CPU will be a bottleneck for all the browsers (and anything else on the system), for most people, however, I would expect the hard drive to have more of an impact on startup times since actually finding and reading the executable could well be the slowest part of the process.
As a rough estimate IE cold starts in 2-3 seconds for me, Firefox in about 4-5 seconds, so roughly double or a little less, the posted results show it to be arround 2.5 times which I just don't see being typical on a modern PC.