You like Mechs, right? There are a couple (just one or two) brilliant mech-related moments in LP3 that probably make it worth your while. There are also some terrible, terrible mech fights that kinda spoil things a bit.
No idea what the PC version is like so check that out first.
Having completed it, and being in the fantastic position of never having to play it again, I would say Yes, Buy It. It's 100% worth experiencing, but bear in mind there will be hella frustrating moments along the way.