The new thief game, as someone who never played the old ones, was a good stealth game, but from everything I've heard about the old ones it was only a decent Thief game.
Also, got fallout 4 yesterday and it's pretty much what I expected as far as game play goes. Settlement building is a bit more complicated then I thought but enjoyable.
I agree, Thief was a good stealth game, but yeah, As a thief game it wasn't really on point. Actually, I can see it being better if the main character wasn't Garret and he was only mentioned in conversation and/or lore bits you find. I also wish they would have stuck to the old thief's theming a bit closer too. OH well.
There are some mods you can get that improve the base building by adding more stuff you can build, try to get a hold of some of those.