I recently did a TTW F3 playthrough and came to the same conclusion. I will say that I actually hated F3's vaults this time around, they're very bland and samey layout-wise and the gimmicks were pretty weak and one-note IMO. I have a stronger appreciation for NV's vaults now.
In fact, all of F3's internal levels felt very copy-paste. IDK if the metro systems and sewers skewered my perception, but after a while everytime I entered a building I kept thinking "I've already explored all this before". NV's outer map may be shittier that 3's but man 3's 'dungeons' turn into green-gray mush.