i have used a couple of times without the side counterbalance in AZ mode and it is perfectly fine Valid points Stu about eye difference,but i dont think it will be critical in binoviewing as it does take a bit of time to get used to them and once mastered you learn how to relax when observing and then it sort of "pops". Changing eye pieces frequently is not an issue in binoviewers as i do the same.It is very easy to do in Denks and Baader mark V,specially in baaders as they have click locks.I had click locks installed on my Zeiss too and its a doodle to swap out.However,i am now swapping out far less as i have powermates to use and now i dont go lower then 16mm pairs of orthos and when i need more power,i just put either x4 or x2 powermate in.Saves the hassle of swapping eye pieces.Denk 2 come with powerswitch and it does work really well giving you 3 different magnifications.But as it has been mentioned before,some people just like mono viewing.