I preferred to play on Marathon/Epic game speed 2 months before because I was able to deploy / use enough military units before they were obsolete. This accompanied with low difficulty level and chaotic planing. I was able increase military power if I lacked it.
After moving to Emperor/Immortal difficulty longer game just gives an opportunity for AIs to build massive armies that I need to deal with. It is just not fun to micro-manage "1000" units ))
And I started to plan actions (because of difficulty and a call for strategy to achieve efficiency). With planing you can deploy and utilize your military units before they obsolete.
I'd like to quote: https://ask.metafilter.com/173833/Turn-me-into-a-Civ-IV-jedi
And another: https://www.reddit.com/r/civ/comments/19dlgs/do_people_actually_use_marathon_speed_or_epic/
For other people opinion refer to: https://www.google.com/search?q=civ4+game+speed
After moving to Emperor/Immortal difficulty longer game just gives an opportunity for AIs to build massive armies that I need to deal with. It is just not fun to micro-manage "1000" units ))
And I started to plan actions (because of difficulty and a call for strategy to achieve efficiency). With planing you can deploy and utilize your military units before they obsolete.
I'd like to quote: https://ask.metafilter.com/173833/Turn-me-into-a-Civ-IV-jedi
The most important thing I learned from CivFanatics, though, which helped me go from "ehh" to pretty good: set goals. Start with an overarching goal (I plan to win via conquest, or by spaceship). Then have mid-range goals ("I want to build The Great Library, which requires Literature, so I'm going to race for that in research", or "I want to take that island next door, so Ill need ships and troops in 25 turns" or "I want to make sure I have iron when it becomes visible, so I'll explore now.") Do everything in service of those goals - don't just do things haphazardly.
And another: https://www.reddit.com/r/civ/comments/19dlgs/do_people_actually_use_marathon_speed_or_epic/
When I was in college (Civ III days) I would play longer games almost exclusively. Now that I'm married, have a fulltime job, etc., I get to play a few hours at a time here or there, or for half an hour before work, so marathon/epic would take me literally months to finish.
For other people opinion refer to: https://www.google.com/search?q=civ4+game+speed