I don't work in pure nature cinematography that much (i have before) most of my work is on feature length motion pictures. That means scripts and actors etc....in this world a side by side is less useful and a beamsplitter is 95% or more of you work on most projects.
Everyone like a nice sharp image.....but when it comes to 3D.....too much IA is just about makes anything unwatchable. Nothing makes poeple take off thier glasses faster than too much parallax or volume.....never head anyone say the corners are blurry so I took of my glasses....in fact in many cases due to a shallow depth of feild most of the image is blurry so.....you get my point. Toom much IA is the main factor in my opinion. It's the foundation of "good 3d". of Course there are other factors.....but I see that as the major factor... your free to disagree of course.
As to your statement that both systems are not beneficial to most films....you are very mistaken. Even with your whale movie example, are you going to show people whales swimming in the water in a wide shot for 60-90mins? No of course not.....you will have interviews, topside footage of the researchers and boat work.....not to mention any closer shots of the whales! ALL of that would require a beamsplitter....
So yes.....in every long form project there are many situations where you need the smaller IA of a BS. Even one of a large object such as a whale.
People have a hard time with Panasonic's 2.5" IA of the 3DA1 and other cameras like it.......so I don't think anybody takes you seriously when you propose that your systems 4" IA has a large "application" and use in most productions.
Certainly if you do lot's of wildlife shooting it can be a more usable IA....but for ME and the majority of work i do and I am involved with it's just not that flexible.
Like I said Pawel, you made arguably the highest quality SxS underwater camera system in the world...... but....100mm/4" IA is ALOT.... you did a great job getting it down to that number but it is what it IS.
I am sure it will be used alot....you just can't argue it is something it isn't.
A DTM car is an incredible piece of motorsport machinery it just can't do what a F1 or a Indy car can do. They are different tools with different capabilities and "performance envelopes"
I just have to state the cold hard facts here.
I WISH a side by side system could do what a Beamsplitter system can do.......that is just not REALITY.
I'm done trying to point out the obvious here on this issue.