The 400 and 70-300 DO are 13 and 10 years old, respectively. Moreover, they were the first of their kind to appear as photographic lenses (I think, as far as I recall, were they actually?). So why do we assume the new DO lenses, should they ever hit the shelves, will have the same IQ issues of their predecessors? IMHO, along with a higher price as compared with their non-DO counterparts, if any, they will offer much better IQ than the previous generation of DO lenses.