I've played both but they lack the replay value of Diablo II (with/without expansion). There are a number of improvements to mechanical things when compared to the Diablo series but I felt that the Torchlight games were quite repetitive after a while. Though diablo 2 had a lot of grinding, I did not feel that way about it at the time. I've spent countless hours in Diablo 2 and Diablo 2: LOD but I could only play both Torchlight games put together for ~ 2 weeks or so.