Been looking at getting one of these mesh wireless kits, like Google WiFi or other, but the price is so high!
Here's my personal experience w/ Google WiFi 3-pack...
I've been using a Time Capsule 802.11ac for five years and since Apple stopped developing AirPort products before mesh even happened, it was time to look elsewhere, so I opted for Google. Got a good deal (15% off + free Home Mini) plus it looked more 'Apple quality' than alternatives like Orbi and Covr with their nasty power bricks. Not to mention that Google's software is much slicker and more stable.
My situation is that I have 250/250 Mbit fiber, but it's actually 250/1000 because the provider has no cap on the upstream for whatever reason. Repeated tests show that I get 230/850 when I bypass the router and just plug a Mac w/ gigabit ethernet straight into the fiberLAN socket.
However, I use WiFi only since the socket is in a terrible spot. The real world speed I get over ac through the TC is as follows:
MBP 2014: 125 down / 400 up (at 61% signal)
iPhone XS: 100 down / 500 up
iPad Pro 10.5: 100 down / 500 up
Apple TV4: 80 down / 250 up
Note: The MPB and ATV are the farthest away from the TC, about 25-30 ft each. I force everything to use 5 GHz by giving the 5G a separate SSID and disabling auto-connection to the 2.4 SSID. The listed speeds are on channel 52. On channel 100 it's even snappier, but oddly it can't be selected manually - neither can 52 for that matter - so I usually don't have ch100 for long, it switches to 52 after a day or so and then settles there. Only 36/40/44/48 are available for manual selection, all of which suck due to congestion in the neighborhood.
So, yesterday I went out and bought me a Google WiFi 3-pack thinking I would get blanket coverage and speed that runs circles around the ageing Time Capsule. The setup was pretty sweet. The setup software was giving me top marks on node placement, internet speed etc. Woah, can't wait to do some speed tests. Tried a few. Absolutely abysmal. I looked for channel selection and realized there wasn't any. Google of course claims that the optimal channels are automatically hand picked for you at any given time. Oh really, because after some 20 restart attempts it goes for channel 36 every time, which is the worst one by far. The whole block is on 36-40, which is why the TC auto-select won't touch it with a ten foot pole, it goes for 52 or 100. Here are the speeds I get on Google WiFi on ch 36 (some may also be 2.4 GHz, another thing you can't stop it from due to lack of manual control):
MBP 2014: 26 down / 103 up (at 98% signal)
iPhone XS: 46 down / 168 up
iPad Pro 10.5: 45 down / 165 up
Apple TV4: 49 down / 152 up
There it is, not quite half the speed of ye olde TC gen 4. This is because it clings desperately to channel 36 like a mother to a newborn. The TC gets the exact same abysmal performance on 36. Who knows, maybe the Google units would scream past the TC on channels above 50 or better yet 100, but even if I should manage to make it try another channel on reboot attempt #91, it's going to jump back to its beloved channel 36. So what use is hypothetical speed when in practical use it's only half as fast as a 5 year old technological fossil?
I'm giving the Google kit another 3 days, then it's going back. I hear the tri-band Orbi is absolutely merciless to neighboring networks and creates a wifi black hole around itself... sounds tempting.