Originally posted by Rondec The problem really is the "value for money" question. Once you bring money into the equation, the question ceases to have an answer.
That's an interesting perspective. Without the "value for money" aspect, then no, the current Pentax lenses are clearly not the best. No lens built for a DSLR (FF or APSC) is going to compete with even medium format, let alone large format.
If you constrain things to 'money no object DSLR lenses', then I would expect FF lenses & bodies to do better than APSC.
If you constrain things further still to 'money no object DSLR APS-C lenses', then I believe Pentax has lenses that would justify the label 'the best'.
Obviously not all Pentax lenses are better than all other lenses! But I think that lenses such as the limited range of primes and the SDM zooms can be considered 'the best'.
For instance, my look at 'standard' primes recently suggests the Pentax 55mm is better than any of the Canon standard primes, including the pricey f1.2. However, saying which is 'better' becomes complex - one will have lower distortion and another better color fidelity perhaps.
So, a very hard question to answer in a reasonable way, but an interesting one.
Just to reiterate, I feel that the Pentax in body stabilization makes the Pentax lenses much better than Canon or Nikon. When I eventually upgrade to the K-7, I will have better IS for all my lenses, protecting my real investment, which is in glass.