Any Oly finder should give you a general idea of size...

Similar negative comments get bandied about concerning APS-C format finders but in truth you adapt fairly quickly and rapidly stop noticing the 'problems' of smaller finders. Can be a bit trickier though if, like me, you occasionally take out a film camera - then you get an idea of how small the digital finder is... OTOH as a specs wearer I find it much easier to see all the information available with the digital version - when I remember to look that is.......