So many on the forums have been touting the benefits to your science of Research Agreements in Civ5, and I have heard certain things here and there such as that the benefits are greatest when your techs in the tech tree are sortof "evenly balanced" or something. Is this more or less the case (in other words, to get the most out of a research agreement, you shouldn't be too deep into the tech tree in a certain region, while lacking in a few others)?

So before signing your RA, you want to be sure you pick up all those 1-2 turn techs? How do the bonuses work? Does it help if you are researching an expensive tech at the time the RA is completed?