I don't know what the situation is with current Lenovo laptops, but the last ThinkPad I bought was very reliable.
On desktop vs. laptop, I bought a laptop for when I travel. This isn't day to day travelling, but the longer trips that I sometimes endure since I live in a remote community. That being said, I far prefer building my own desktop. The main reason is servicability since most of the components can be swapped out when they fail. Of course the irony is that desktops fail less often because they are transported less often. The other part of the reason for building my own desktop is because it's fun. Laptop purchases are a chore (in my humble opinion) because it is a matter of finding something that meets my needs at a reasonable price. Desktops building is fun because I get to research the various parts and get exactly what I want.