On new Androids BT is wonderful, all the switching is in the tray menu. Turn on headphones, it connects, turn them off or use the switch to go back.
I also don't ever turn Bluetooth off though, or even have the button to do so in my quick shortcuts, so things might be different if I did.
And I do remember older androids being annoying, since you couldn't switch away from the headphones in a hurry without turning it off.
But as is, I'm pretty much pro-3.5mmless and don't think I'd ever want to go back to cords.