I used FM2's for years and never wanted anything more electronic. If you're well practiced, the manual cameras are very quick to use.
Some things to consider - you won't see the potential using a 400 ISO film. That's about like 3200 ISo digital, grain-wise. Go Velvia or Provia. I would guesstimate that a 400 ISO colour print film is about like a 4 megapixel digi, and Velvia like about a 10 megapixel, albeit a bit grainier.
Also, you won't see it's potential with that old Vivitar zoom. If your Dad had the 50mm standard lens, use that one. Otherwise all you're doing is comparing old, pioneering, second rate superzoom technology with the mature technology of today's zooms. I had a Vivitar 28-105 of about that era. It was awful.
Phil's right about the market placement of the FM2, but it was a pretty-well unique camera, being fully mechanical, not just manual. No battery needed, except for the lightmeter. Only Pentax (K-1000), Oly (OM-1) and Leica made fully mechanical cameras then. The FM2 was the best, and most pros had one on hand, especially for remote or cold climate work. Yes, magnificently small and light for the image quality, and fast flash sync, too.
In my h, o., the finest hand camera of them all, ever, red dots included. Have fun.