I'm still amused at the irony of some Android fans portraying themselves as counterculture rebels simply because they bought Android phones... and promptly crowing about Android's larger market share. It's like declaring that you're a true indie music fan because you listen exclusively to Top 40 pop. You're a power user if you bought an Android phone primarily with customization as a major factor, but going with the majority platform and a large manufacturer? That's about as conformist as you can get.
There are people who use both Android and iOS who are guilty of thinking they're counter-culture because of their choice of phone let's be far about it.
People who use Windows mobile may be the most "counter-culture" if they know all of the disadvantages of that platform and still choose it. I know one person who has a Windows phone.
What should be important is features you want in both the hardware and OS (and the apps that will run on it). The features I want are only offered (afaik) by Samsung and LG and Samsung is moving away from that. Although I may look at a Note 4, as well as the LG G4 for a future upgrade.
As for power users it's probably divided by tiers. The apex power user is the one who gets root access to their phone to wring every ounce of performance (and/or customization) they can out of it.
Others who do less fall into lower tiers. But they all do more than just turn on the phone set up contacts and install apps.
As for me all I did was enable developer options and set up Apex launcher because it is noticeably smoother and offers more options than the customized UI that the manufacturer put on my phone. I also installed a file explorer that provides more information and is more capable than the stock file explorer.
I don't really consider myself a power user as far as phones are concerned though.
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