About the slowness - is it just on launch, or does it keep being slow if the app keeps running? A few hundred ms is indeed a deal-breaker for standard Unix-y CLI app that might be chained with 5 other simple apps. It doesn't seem like a big deal though if you're launching something like Chromium that you might normally leave running for weeks.
The problem is that if you use chromium in any automated testing suite, it can get restarted after each test making a test suite take much longer to run.
For me it's just on launch. More precisely, the period before the application actually starts to launch. I guess it has something to do with mounting the various file systems and setting up the connections or whatever it is that it does.
I've had to install Chrome to try a thing or too (so not as a daily driver) and I haven't noticed anything weird during use. I've used Jetbrains' PyCharm daily for a few months and no problem there either (although that is a "classic" snap, not sure if it matters).
