I would ask when you played last and what you and your friends want to do.

If you want to continue an old game with old characters then I would probably suggest not bothering.

If you want to start a new game with new characters you will see a ton of new changes to progression especially if you played before H&H dropped. I would say it is definitely worth playing again just to adjust to all the changes.

So really it depends on what you and your friends want or hope to gain from playing.