Does Flex work well?

I'm thinking of getting a phone with 8GB storage.

This isn't great as its not enough for anything much. However, if I use Flex with Android 6, I should be able to use the SD card as internal storage.

How well does Flex work? Does it work with all apps?

Are there any downsides to relying on Flex?

Thanks.

 

I think the Moto G has it, or will soon?

http://www.androidstandard.com/android-m-for-moto-g-features-and-release-date/