Downer, I agree that taking cities early is hard. Odd, since early on, before I released the mod, people were telling me that it was too easy to take cities early, so I originally had increased city defense and heal rate. I changed my mind after trying to actually take a walled city with only swordsmen. Now the only change the mod makes to the default settings is to increase the hill bonus slightly, though for the next version of the mod I have slightly increased the effect of garrisoning a unit in the city from 20 to 25% of the unit's strength. I don't get around to conquering people until at least the middle ages, and by that time I feel that things are well balanced.
Windscion, I agree about Gandhi. I played as him once, and it was absurdly easy to be a warmonger with his bonuses, so I have decided to nix them some for the next version.
For the research costs, I go by my own progress as well as the AI's. I'm playing on Emporer now, so maybe that skews things a little for some people. In my current game, for example, before I made the last increases, Gandhi had oil in the late 1700's, which shouldn't happen.
Note that this was on a large map with only 8 civs and 16 cs's, so everyone gets to found about 10-12 cities. If you would like to set your default settings to this, you can do so by going into CIV5Worlds.xml. It's just a text file, and the settings are readily apparent when you read them.
If anyone likes, I can show you how to set your game to reveal the map with any tech you wish, then out-comment the reveal and re-start as normal. It's great for getting a good starting location for each game without wasting time on normal exploration. Myself, I usually go through about a dozen maps before finding one I like, so this has saved me many hours.
Getting a strong starting location each time gives you a more consistent game experience, thereby letting you choose a better level to play on. (Imo, fewer AI civs give you stronger opponents, too.)