I use it daily as my IDE. I find that startup time is indeed slow as a dog, but once it is up and running (and it's typically open all of the time, so startup time isn't a real issue) it runs fast enough. At certain times I notice small delays on more complex ops compared to sublime, but nothing significant. The main pro's for Atom, for me, are the way the eco-system is developing, the open-source nature of it, and I'm slightly more happy with the interface. If push came to shove though, I could be happy in either sublime or atom.

The difference in speed in these editors is so small that, if you find it's having a measurable effect on your productivity when coding, you may want to re-look at how you measure productivity or indeed how much time you're churning out code versus other development activities (thinking, planning, testing, talking).

The issue with speed in an editor isn't so much that if your editor is slow that it makes you code faster, but that if your editor pauses, it interrupts your thinking and prevents it becoming very natural and quick to use, like an extension of your mind.

So it's not so much '60 seconds of waiting for the editor in a day', as '2s delay opening that file so my brain switched to thinking about something else, slowing me down for 10+ mins'

I do use it as my daily IDE. It is MUCH slower than Sublime, but I'm trying to ride with it through its bugs and builds. I occasionally use Sublime still, and go through periods of time where I use RubyMine.

I like Atom too, but the startup time between the 2 is night and day. I also get really odd Atom behavior, especially on full screen.

I think startup time is a non-issue given how you can just leave it running in the background.

I use my text editor for a bunch of ad-hoc edits, not just working on projects, but you are right. Speed is less important than buggy behavior (I say this not as a hater, but as someone who is working in Atom all day)

I've only experienced bugs in the early days where you couldn't precisely select a character with the mouse and everything else I've experienced is usually third-party plugins. At least Atom does a great job identifying with plugins are causing issues and collects deprecations and exceptions, and those can be reported by one click. That's why I think Atom brings unique solutions to common problems and, yes, it's a bit slower, but if it becomes popular, maybe it can get a native renderer - who knows. It's too early to predict its fate! So far, given it's infancy age, I think it's done a great job!

My Atom is up and running all the time until there are new app updates, which require restarts.

Have you tried Adobe Brackets? IMO it's a lot faster + you get CSS hints from .psd files. Also you have inline editor, which is super useful.

It's still a lot slower than Sublime, but it's fine for me. (im not primarily a developer tho)