Artpunk: Thanks for the links & the article. That photo of the horse is beautiful. Is that shot with an original Diana or one of the new ones? The review on the ToyCamera site says the newer ones have no 'sweet spot'. Have you found this too?
The horse photo is taken with a Diana 'plus' - if you click on the photo it should bring up a 'lightbox' window where you can scroll through a few examples photos including a shot from the 'original' Diana 151.
Regarding a 'sweet spot' - well some of the original Dianas didn't have this hypothetical sweet spot either, as each lens had it's own unique attributes, some more appealing to the toy camera enthusiast than others. With the Diana +, some people think that the manufacturing quality is 'better' with more consistency, perhaps eliminating these "sweet spot' characteristics. The same is also said of the newer Holgas making them 'too sharp' according to some.
In practice however (coming back to the new Diana + lenses) I have found the results from them to be 'consistently inconsistent' and have often been pleasantly surprised (as I was in the Sleeping horse photo) Note that Michael's review on tc.com is simply referring to the one Diana + that he was sent for review, I have noted slightly different attributes in the different Diana + lenses that I have used, but I tend to get them mixed up (as they are removable) so haven't noted if any particular lens gives a predictable result. (I'm a bit random like that)