The response time for turning on/off the switch is very fast and Alexa/Google Home integration is great.
For Alexa, you should change the device type to light if you want to have "turn off the light" command working as expected rather than Alexa asking which device with name light because by default Alexa would recognize it as "switch". While it is technically correct, it is certainly not helpful for majority of people.
For Google Home, it has a bit of delay in recognizing device state initially compared to Alexa, but it automatically recognize them as light when device is named as "xxx light".
With all the good things mentioned, I like to mention a big limitation of Kasa products. They have quite severe limit on Smart Actions. You can only have 3 smart actions enabled per account.
For example, you can create a smart action to turn off the switch automatically after x minutes making this switch a count-down timer switch, but you will be limited to only three devices for your account.
Perhaps TP links worries about this service costing too much for them to run cloud services. In any case, TP link should be more clear up front on this limitation so that potential buyers are aware of this limit before purchasing the product.