i like the fact that i can have a list of session at mouse reach. i like that i can do stuff like have sessions with different color schemes, or sessions that run a command on startup.
i like the fact that it's scriptable. at my previous job i had a python script (that i could recall from a button within securecrt) that would enumerate stuff off consul and create/update sessions on the fly, with all the necessary hoops in place (eg: setting a jump host).
i have to say, i also have some nostalgia of my first job where we used securecrt heavily (or maybe i'm just nostalgic about being 24 years old? i don't know...).