I can obviously only speak for myself: I started a new playthrough just to see what has changed. So, worth? I've only just picked up the relic, no sidequests/gigs/etc done yet.

Some things feel new, eg. I don't recall the arasaka tower had destroyable walls or somesuch before, but could be I just managed to sneak/shoot better before. Mostly the things that are changed/feels changed are fairly small, apart from the skilltrees and mechanics.

Also, the PL questline apparently opens when you're done (?) with voodoo boys, so I kinda felt that I want to tackle that when it's given to me. But with the new enemy scaling (love or hate it), I guess the dlc mission(s) stays relevant regardless of your level.

But ultimately up to you, I guess. Flip a coin if unsure? :P

I started a new playthrough and I'm really enjoying it. The story is the same but the new trait system makes it feel like a proper RPG, and the combat feels more intentional.

There still 3 days until release, I'll probably stick with my new character through the expansion even if I have to wait a few days to reach the new content.