I'm not sure but in Spectre we can declare the parameter and get the gm of transistor directly or go to the results and then browse to get the transistor level power screen in tht u can get the transconductance. I forgot the path,but it is from the Results menu.
Please try, if any prob do reply.
once you finish simulation, what you can do it to go to the simulator window and you have an option to print operating point parameters, choose this option and you can see almost all the parameters. i agree that this is not convenient for those who are used to using hspice and eldo.