You might be right. I considered that, but it doesn't have as much of an impact factor on the user, which is really important for getting the word out about performance (why the site exists in the first place).

I probably doesn't matter too much as long as you have a ~3Mbps connection or higher (see Mike Belshe's "Effective Bandwidth of HTTP" graph on http://www.belshe.com/2010/05/24/more-bandwidth-doesnt-matte...) because the TCP transmission rate can't ramp up high enough on each object to saturate the connection. It's possible, however that the objects will interact with each other by causing differing queueing latency and possibly loss in the bottleneck router and by changing the order of scheduler events on the client OS. Also, it may be better subject the two pages to the same network conditions (at least in the last mile) while they're loading, esp. on mobile.