Setup - I own a Google Wifi router, and I've read a lot about issues with the router and 2.4ghz smart devices. For whatever reason, I couldn't get it to set up, but after some research I read about the solution. Here's what you do: flip your light switch 3 times so the bulbs flash, go into the Smart Life app, select 'ceiling fan' under lights, then run outside or maybe 20 feet away from your wireless router. Your phone will then pick up the 2.4ghz frequency instead of the 5ghz frequency that doesn't work with these bulbs. From there, set up should be easy. I got this to work on my bulbs, no problem.
Brightness - pretty good! I like the incandescent and daylight settings. The colors aren't as bright as the whites and yellows, which is to be expected, but they're cool.
Functionality - these bulbs work effortlessly with Google Home (and Alexa, i'm sure).
Overall, I can't imagine there's much point in getting the more expensive bulbs. These just work.