Now a lot of things I miss a lot. The modularity, latches, ThinkLight, the upside down Thinkpad logo on the outside shell (oriented correctly towards the user, not the other people in the room), 7 row keyboard, good Fn keys functionality like media keys. The T400 that I regularly stood on to impress people how sturdy it was. But all of these things cost a lot in terms of weight and size (except the logo which was just copying the change that Apple made).
Just so you know the context: these are the machines I used a lot. T42p, R60, T400, T440s, T470s, T495s, T14s Gen2 (current).
If you respect the sturdiness vs. form factor trade-off, I believe build quality has gone up with every machine I bought.