[ponker]

Something is pathologically broken for you. Don’t know whether it’s client side like a corrupted browser or service side like a malformed attachment that is causing Gmail to thrash. Chances of course are that the problem is on your end.

[PostPlummer]

100% sure. I have been using gmail since forever on all sorts of networks and devices and never ever has taking "being useful" 20 seconds, unless there is something very wrong on my side.

Weirdest thing is that an add-on makes it faster, how's that even possible without a serious MiTB problem?