I've been using on rounds, typing on one now btw. So far it sucks for actually accessing the EMR, looking up info, and entering orders. Im on Epic, the cantos app sucks, and so does the Citrix receiver. Too slow and laggy, you have to log in 2-3 times to even access data, and without pristine wifi access it drops off. Our hospital wifi is awful. Also, dragon and the like offload all the speech processing to off server, and it's slow as hell. It won't pull up PACs images either...
Where it shines is information storage for access of texts, notes, the like. I've got the green book, acls cards, pharmacopeias, scanned copies of text books like Harrison's. My coat is near empty now.
What it really needs to replace a desktop... Fluidity like safari, a better UI, and a seamless dictation integration. Hardware is there, but the software not so much.
Btw, rather than a keyboard case, I place it in a clear clipboard case that opens up so I can keep my notes and other papers on it. Also, I've seen some people with MacBook airs on rounds, and those seem much better but not perfect.
