The River (as affectionately known in Boston) is a great layout, one that I had the chance to finally see about a month ago. I unfortunately played it only two days after aeration, so I didn't get the full effect of the greens, which would be the highlight.
It's certainly a "give and take" course in that you have to make birdies on the easier holes due to the fact that you will make the inevitable # of bogeys. I think technology takes away some of the challenge at CR, as a couple of holes can now be overpowered (#12, you can hit it all the way to the bottom, 70 yds from the green, beyond the funky lies, #15 especially, as a 260+ drive can now roll down the hill, so you can have a short iron into this par 5 in 2)
Despite this, you have to be on your game to par holes like #5(uphill 4 with steep back to front green), #11 (245ish par 3), #17 (190 with two shallow tiers), and 18 (long 4).
As for it being top 100 classic material? If Essex CC is in the second half of the top 100, then CR might barely miss out. I believe Essex is a slight step above.
Also, I believe a bit of the "climate" issues could be due to the fact that much of the course seems to be built on ledge rock, which creates the odd bare spot or poor-draining low area. Maybe our GCA green section can correct me here.