Index and oplog doesn't affect the client though.
@SkyRooms That could be the problem. I don't have any experience with data that changes so frequently though, so I really don't know what the limits are. Still sounds weird that it would freeze the browser I think. What happens if you remove your own code that uses the data and just subscribe?
Also, Meteor DevTools is pretty poorly optimized and can definitely hang the browser, so try without that maybe
My admin>customers page subscribes to all 2300 customer users, with up to 40 fields each! Terrible optimization I know, I'm in the process of overhauling the whole app. But it still runs okay!