Ofcourse the huge volume is great, it's awesome! But by only offering single high-res .jpg files instead of image tilesets just makes the viewing experience less than pleasant.. Downloads are slow, the pages are unresponsive, and I can imagine it's going to cost them tons of unneeded bandwidth.
I agree that "deep zooming" is desirable. Looks like Micrio doesn't support the International Image Interoperability Framework [0], something I think a museum would be interested in. Oh, and I hate that http://micr.io uses a fullscreen background image that highjacks the scroll wheel.
Thanks for your reply, you're right about that. Currently we've only been developing micr.io based on wishes we received, that includes features such as hotspots, tours, etc. See https://tuinderlusten-jheronimusbosch.ntr.nl/en for its first release. We simply haven't had the time yet!