So I've got mostly primes:
K-7
15mm DA f4
35mm FA f2
50mm M f1.7
100mm WR f2.8
55-300mm DA f3.5-5.8
and the 18-55mm WR kit lens
I'm quite happy with this setup and think that's a reasonable spread of focal lengths. It'd be nice to one day get the 31mm FA if I can manage to - probably because I like the FA 35mm so much.
At the moment if I need WR I've got the 18-55mm unless I turn to the 100mm.
The 18-135mm WR looks good, but will it leave one itching for the 50-135mm DA*? and then it continues you then want the 16-50mm DA*?