I have been using this app on my Imac for about 6 months now and have had no issues, Works as if you were on the webiste with the same interface. I does use about 98mb of memory, but if your going to run a lot of apps in the background you have to expect this and prepare you computer with enough ram to handle the tasks your gping to give it, that’s way I run 32GB on my mac. Reading some of the other reviews, I have not had any of these problems, the apps opens fast and works the same as if you were on the website. This app was well worth the money spent and I use it more to control my nest than the app on my Samsung note 3 or note 10.1 (2014) tablet. I definitely recommend this app for a convient way to control your Nest products.
I would like to see more options for control and longer energy usage history (2 months), but that is up to Nest to fix and has nothing to do with this app.
Update: in last 2 weeks Climate has been diconnecting and having a hard time reconnecting, app seems to just sit there spinning and nothing happening. What happened to the support? Been using for a couple years and all of sudden these issues, please fix, thank you.