Play the map. Type in "timedemo 1" (minus quotes) into the console. Then type in
"stat fps" (minus quotes again) and watch the poly number. Keep the poly count to under 100.
Play the map for a while with the timedemo running. After say 30mins, type in "timedemo 0" (same as before) and look at Average, Highs and Lows. Generally you want a high Average, high Lows, and modest Highs.
Wonder if that makes sense? Anyways try playing it in software if you've got a monster machine of a PC. That way you represent other people better.