I have a L1200 from 1979 (I think. It is written on the column), with the colour head. I also have a DII (not to confuse with the D2) from Omega. The Durst is my main enlarger as it is solid and stable. When I want more contrast, I go with the DII.

Since I got it (2 or 3 years ago), I met only one issue: the nylon universal joint used for the focus telescopic bar (sorry, I'm French so I don't exactly know how you call it), broke. I replace it by a stronger one (the one use for the colours controllers).

But about the nylon gear inside the head, I didn't met any problem with that so far. I guess the ventilation for the lamp is doing its job well.