When I was offline for nearly a year back in early 2005 after moving house, I had MAME 0.89 running on my 1.2GHz Celeron (P3). When I finally went back online, MAME 0.103 was out. I updated to that and it worked fine, aside from some missing ROMs which were obviously changed during such a long break from the internet.
It's just the same old 'use this MAME, it's faster/better than the new one' that has been around since 1998. Using an outdated version of MAME is only worth doing so if the drivers have not changed significantly. By doing so, that means Bubble Bobble will be glitchy, Donkey Kong will have incorrect sound, games that have been promoted to working since then, and any interesting games added since 2004 will simply not even be there. I would avoid DirectDraw mode too, unless you really enjoy playing Street Fighter squashed and letterboxed in 800x600 mode, or Galaga with horizontal scanlines...
Coincidently, MAME 0.84 turned seven this week (July 2).