My take would be yes they are very good.
13 is cracking par 3 played from a variety of different tees that Colt sculpted into the hill, lovely rear swale
14 you might be right that bunkering is a bit out of play now but that's only for good golfers and relevant to lots of holes/courses
15 is slightly weak as a looker IMO, but its a strong hole and perhaps a half par which like 14 and 16 are nice features ending a round
16 is weakened only by the marginal blindness, still has very strong bunkering, very typical Colt, most courses this would be a standout
17 is awesome
18 has the history, the clock, the tree, the bunkering.
There is still a lot of variety in the holes.
So I find it hard to agree yours is fair assessment. If you look at the first 6, again a lot of variety, perhaps 3 is weak hole but in the scheme of things most welcome. 7-12 is the quirky section which Colt took us over the best/toughest land. 11 is not much IMO, I quite like 9 but I could see people not liking it. Sunningdale = a lot of variety for me.