We didn't collect precise timing data, but I hope to release the code soon, and it's pretty easy to setup a test similar to ours, e.g. with high volume hashtags such as #nowplaying.
What I can tell you is that we published messages in batches, closing a batch every 5 seconds or 100 tweets (at the highest traffic rate, we were receiving and publishing about 100 tweets every 1-2 seconds). This is way below the quota limits.
On the subscriber side, we received batches of at most 10 messages. I didn't investigate if this is a limit or a config param. The sensation was to receive the messages pretty much instantly (I was looking in parallel at 2 shells, one publishing and one receiving), but again, I don't have precise measurements.