How big is your project that you find atom slow? I have gone back and forth between atom and sublime 10 times in the last 10 minutes and I have not found a single reason why anyone would notice a lag in a project of just a shade over 10,000 files. The difference in speed is completely imperceptible.
Not saying I love atom more than any other editor (I typically use terminal vim) but in my experience over the last week, any complaints about atom's sluggishness seems either outdated or wrong to the point of absurdity.
All that said, Sublime is not my daily driver. I use JetBrains products for that. I mostly use it to jot down notes that will eventually be transferred somewhere more permanent, temp access tokens for APIs, small snippets, JSON files, Mardown files, etc. If my main use with ST3 wasn't frequently opening and closing it, relying on its great performance when opened with my actual IDE(s), and abusing its second-to-none ability to keep files saved without actually saving them to disk, I may feel differently.
Different guy here, but I don't thing project size has much to do with it. For me it's UI for the most part. Most of the time I can see, how the moment text goes from "simple text" to the "highlighed text" (and all of the formatting too). I simply can't stand this. Same happens when searching a large file (I do work with logs pretty often). But this problem is solved in Atom for the most part - you still can't open files larger than 10Mb...
And as a separate issue - the latest update made it impossible to update Packages for some reason. All I'm getting is "undefined" error.
Thank you, random citizen.
If ST3 had the same features (basically, more support for friendlier plugin integration) it would totally devastate those, apart from in price (which should be irrelevant for professional developers anyway).
But even as it is now, it's way handier (due to the snappiness) for everyday coding than VS Code (Atom is so slow it doesn't even qualify).