Nonsense. I just ran a load test against WP yesterday and with a traffic load (from tsung cluster) peaking at 430 req/sec, it was easily served by 5 t2.micros

Nonsense. I just ran a load test against WP yesterday and with a traffic load (from tsung cluster) peaking at 430 req/sec, it was easily served by 5 t2.micros running Varnish + WP (behind Apache no less) + memcached. The load test included random search strings 50% of the time so half the tsung visitors were getting live service from Wordpress.