One thing I've noticed recently as I've been gaming online more (or at least trying to) is that my connection speeds and pings become abysmal from about 4:00pm - 11:00pm or so. According to speed tests, downstream speed falls from around 6mbps to about 1mbps. Ping times vary, but as a baseline, pings to the U.S. seem to increase by about 100ms on the whole.

For reference, I'm in Palmerston North, on the Pro plan. I assume this is pretty much the peak time for internet usage in NZ, but is the effect normally this drastic?