tried to play multiplayer with mac app store version 1.3.2053. friend tried ipad and mac.
fun but ran into a lot of major bugs and lag. both in US with broadband, shouldn't lag so much.
main bug was item duping. a lot of times, we both picked up the same item and got 2. when we started having only one person try to loot stuff, sometimes that person would get two copies of the same item picked up. item duping happened all the time.
we also got a bug once where we couldn't save or rest. no someone wasn't trying to talk to us. we travelled to another zone and still couldn't save or rest. had to use the auto-save from travel to get a save to load from. no idea what caused this. noticed it in beregost.
we got quite a few app crashes when trying to join games or reload mid game. sometimes a couple in a row just trying to get in the game and start. rarely crashed while actually playing and not trying to reload.
for lag, quite a bit of delay for non-host, makes it really hard to kite safely, much more lag than our pings to each other. enemies sometimes teleport instead of walking smoothly. also, zone changes would cause a lot of lag and waiting for some reason.
hope this helps. it's fun enough to put up with this anyway, but it's really pretty bad lol.