Red Tail is a very good golf course, among the best publics in the state for me. It has an unusual number of subtly strategic holes for a public course, especially on the excellent front nine. There are a couple of blah holes on the back side, but I would still take it over any of the publics in the Plymouth area. It's also a very good example of Brian Silva's architectural style -- and therefore a good example of the New England public golf experience.
Waverly is a big course and has some memorable holes -- most notably the 17th, which is kind of like the 16th at Cypress point minus the views and with a scrub-filled crater instead of the ocean (I know, I know, fairly imporant differences). But overall I didn't find it as interesting as Red Tail, or the Nicklaus course at Pinehills for that matter.
I would give Red Tail a 6 on the Doak scale, Waverly and Pinehills Nicklaus a 5, and Pinehills Jones a 4. Red Tail is quite a ways away from Boston GC, though, so I'm not sure that I would recommend it for an afternoon round on the same day.
There are quite a few private courses I would recommend over any of the publics: The Country Club is at the top of the list if you can swing it, but that might be hard to do, followed by a tier of Salem, Myopia, Essex, Charles River, and Kittanset, all of which would be in the Doak 7-8 range for me. Salem and Kittanset also would be a decent trek, in opposite directions -- Kittanset is on the Cape, but probably not a much longer drive from BGC than Salem or Red Tail would be. Closer to Boston, besides Charles River, I'd second the recommendation of Brae Burn and add Winchester (an early, slightly quirky Ross that is a personal favorite) and Dedham Country & Polo Club (originally a Ross, with renovations and expansion by Raynor I believe).