TVs with built-in Android... quick?

I've had an Nvidia Shield for a while but its uses are starting to deplete for reasons I can't be bothered going into, with the only real use being to run Kodi and watch TV shows and movies I have stored on a hard drive. I'm long overdue a TV refresh and I've been considering one that runs Android TV for the (presumed) versatility and array of apps you can run without extra equipment. And according to guides I've read online, it would be able to run Kodi too.

But one bugbear is that the Shield takes an absolute age to start up. I might've misinterpreted the post but I vaguely remember someone on here saying it takes ages for an Android TV to start up too.

So can anyone with an Android TV help me answer this question - does it really take ages to just turn on an Android TV and watch something, or does it depend on whether you're opening an app? I can forgive it if there's loading times to run actual Android software but not if I just want to watch what's coming through my HDMI port or my aerial.

Any info would be appreciated

I have a 2015 Sony Android, it's fine if woken from standby status, when started from cold, the loading of the base OS takes a while and if heavily loaded with apps starting them all, or preparing them for execution can impact the overall start-up time. Recommendations are very meh though and don't tend to follow watched content.

A reminder that Android TV is being replaced by Google TV which at present is effectively a rebadge operation, but has scope for additional features in the next gen apps. The discontinuation of individual Android TV apps in favour of enhanced Google TV ones can't be ruled out.

Finally, I'm using it as an app backup access device, choosing to use AppleTV 4K, Firestick 4K and NOWTV 4K boxes in preference now.

Android always takes a while to get going, you only have to look at the mobile phones. The load time on the Fire Stick (which uses a butchered version of Android) is actually longer than the mobile phone version.

This article below seems to suggest the average start time is 40 seconds for Android TV:
https://www.firstpost.com/tech/news-analysis/from-better-stands-to-faster-boot-times-here-are-7-things-id-like-to-see-in-smart-tvs-this-year-8242661.html

Seems to my mind to be a long time, however seems to be an Android "feature". iOS is probably no better though to get it going in this department.

If I were cynical I'd say it's partly a ploy to make you reluctant to turn the thing off. If I were cynical...

Beware Android TV on Sony TVs runs at a fixed refresh rate (or at least every Sony Android TV I've seen has). This fixed refresh rate is either 60 or 59.94Hz - so all 25 and 50Hz European content has a nasty added judder.

As others have said - booting up an Android TV takes a reasonable amount of time (similar order of magnitude to a Shield TV or Google Chromecast with Android TV) - but when you put it in to Standby it goes into a low power mode rather than fully off (though I think Sony TVs keep waking up randomly - and doing things like triggering AVRs connected to them to power cycle), so switches on immediately. If you do a full shutdown - then it takes the full boot time to come on again.

Thanks everybody