The power items appear to only give the EV's of their relevant stat.

[Karba]

I know the power items got buffed to give 32 instead of 8 but it seems to not give the any base EV, the also means if the defeated Pokémon usually gives Speed but you are using the power bracer you just get 32 attack and no speed. Is this intended?

[Yeshua_Kristos]

It is intended. It makes it so while you're holding the Power item you want EV's for, you can grind on any mon. No more trying to look for Oddish just to get the most out of the Power Lens, for instance. ^_^

[Karba]

Nice, it has made grinding way easier just did not know it was intended. Thanks :D