Is it just me, or do you sometimes end up waiting too long for SD when it's clear that neither team is going to make any progress?....
Well, I've got a few ideas on how SD can be changed to eliminate this flat-spot in the game:
Instead of a set time-limit until SD is reached, make it so that it comes a fixed amount of time AFTER both teams reach Stage 3. Maybe 10mins could work, so if both teams are S3 in 15mins, SD kicks in at 25mins. This should be enough time for both teams to build all their S3 defenses. The hard-limit on S3 could be left in place, or removed entirely. If the game goes for 30+ mins and both teams aren't S3, either (A) one of them is dominating over the other, in which case they shouldn't need SD, or (B) the whole game is just full of no0bs / campers.
Alternately (and this one sounds a lot more fun to me) - Each team reaches SD independently, sort of as a Stage 4. Once your team reaches Stage 3, the top of the scoreboard shows "X kills to Sudden Death". This has the added bonus that Luci Vs. Dretch, & Tyrant Vs. naked human just to boost kill count is ANTI-productive for you team (at least for a period), as it will only bring YOUR team closer to SD.
In both cases I believe this would make the game faster, and less prone to stalemates that end in a draw. I realise that SD is often considered to favour Aliens, so perhaps the numbers could be tweaked (in the second option at least) to give humans statistically more non-SD time than aliens - i.e. kills required for human SD is 1.3% that required for aliens.
My programming skills aren't really up to scratch to do this myself, but if anyone else thinks it's a good idea, please feel free.
Flames welcome if humorous
