I dont exactly think thats true. As for changes, a few have mentioned that the K712 is ever so slightly warmer than the Annie when they both use the same pads. Just going off what my friends here have told me. I personally dont find them different enough and would just get whichever is cheapest. HAD the Annie still been sold with the older memory foam pads, I'd go for those personally, since I prefer its more intimate presentation. Apples vs a slightly less juicy apple. I love both.
That may be true as I haven't tried the Annies and my K701s got sold just after I obtained the K712s so I did not do a long term comparison. The 701 I believe are considered the brighter of the bunch and with the 712 I found them very close, again with long term listening I may have gotten to notice some differences.