It's annoying that you have to stop one research before starting a different one ... no I'm not complaining that you can't have two going at the same time that's a balance issue that I'm not prepared to argue one way or the other but in most games with such things starting a new one stops the old one for you but in this one you just can not start a new one till you stop the old one instead of having the starting of the new one stopping the old one on it's own