Yes, I used that bootvis.exe.
I think it sucks. It produced a large log file and did not do much to the bootup time. So I removed bootvis.exe and the log file.
Having got rid of the trace.log by re-installing Windows XP ( for other reasons though) I do not want to find out the hard way if bootvis.exe secretely started the mess...
But I share your suspicion. Would be a great idea of Microsoft's to let you save a few seconds booting time at the cost of filling your hard disk with junk!
_rainer_