I've recently checked out Microsoft's Surface Earbuds, which at $249 cost a lot more than Google's option ($179). The Surface pair are also much larger and look like massive gauges in your ear, while the Pixels are slightly smaller - more like mini gauges in your ears. Mak and Pixel Buds product manager Sandeep Waraich pointed out that the Pixel Buds sit flush in your ear, though, so you can't see them jutting out when you're looking at a wearer face on.
Yet, I found Microsoft's earbuds had a more snug fit -- thanks to their sort of lock-and-key design that have you twist the headphones after sticking them in your ear to keep them in place. The Surface Earbuds felt less like they would drop out, even after I jumped around a little bit, although I didn't feel as if the Pixel Buds were about to fall out, either.
One difference I can already tell, just by having had these things in my ear, is the way the Pixel Buds seal your ear cavity. I noticed significantly less noise once I tucked one of them in my ear, muting the surrounding furor in our chaotic demo area. This might help you hear clearer sound once these earphones actually start playing sound.
I also got to hold the wireless charging case, which Waraich described as sort of like a river stone. It certainly felt smooth, rounded and dense enough to come off premium, but wasn't too heavy. Waraich and Mak encouraged me to keep flipping the lid open and close, and the hinge certainly felt smooth. It had a springy mechanism that was satisfying to fidget with. The charging case will provide up to 24 hours of juice for the buds, which on their own will last 5 hours of playtime per charge. Best of all, they charge via USB-C.
Since these weren't working units, it's hard to tell anything else about the new Buds. Audio quality, Assistant skills and the responsiveness of the touch controls on the headphones' surface are things we'll have to test when functional versions are ready. The Pixel Buds will be available in spring 2020, so we might have to wait awhile longer.