I'm another who is slightly torn between both options.
Whilst I love the four paneled releases and can see some of Arrow's brand identity slipping away with the conversion to the Unlimited Edition, it's definitely a matter of longevity in regards to Arrow Video as a viable business (look at what happened to NoShame
As many others have said, it is the film that matters the most, and the Unlimited Edition becoming the standard would certainly help Arrow cut costs on both packaging and having to release a separate DVD of the title in question. We may then see more titles being released because of these savings on packaging.
Also, the Unlimited Edition is still a great package, in my opinion - certainly equaling the likes of Eureka and BFI in regards to the double play edition complete with booklet in the clear case, but with the addition of the flip-side artwork. Again, there are not many cult labels employing this value-for-money package set up (Synapse do come close).
I'm another who doesn't bother with the posters, although the artcards were a great addition to the few titles they were included with.
I'd hate to see Arrow Video go under for the sake of a bit of cardboard and paper...