I'm having the exact opposite experience with Chromium: Sometimes, two to three tabs (regular websites, no videos, no fancy stuff) already make it freeze. My Firefox, in contrast, runs smoothly even with dozens of tabs open.

Firefox is often faster than chrome for me on my 2015 MacBook air

The DNS thing is probably caused by Firefox's OS-agnostic DNS. You see, in Windows Chrome will use IE's networking stack (so changing your IE proxy settings changes them in Chrome) if you have the "enterprise version" installed. Also, if your company has installed "security software" that screws with web requests and/or DNS resolution in order to "keep you safe" it'll treat Firefox's outbound HTTP requests like they're coming from a script and treat them with heavy suspicion (which slows everything down and can even result in timeouts).

It's super annoying. This is the state of things at my workplace and it's ridiculous.

> It also seems to get stuck resolving DNS sometimes, which is probably an artifact of the corporate network, but Chrome doesn't have that problem.

OMG I thought I was the only one running into this exact same problem! This has been a deal killer for me.

I know this is contentious, but I think the problem might be that you're using a razor-thin device with extreme thermal throttling problems. I experience no such slowdowns on a 2011 Acer econobook with an i5 and 4gb ram.

Agree with the performance problem (initial rendering). Mid-2015 MBP 15'' ("the best laptop ever made").