Most of the time, my searches yield results that go back no further than April, 2004 (when the new software was installed). Occasionally, however, I get results that go all the way back to May, 1998.
Over the last couple of days, Flyertalk has run very slowly at times (when no other website has been slow) and it seems like the search function times out on me during those sporadic slow periods.
All in all, though, search generally works.
Now if only we can get people to use fewer 2 and 3 letter abbreviations in their posts and titles.