The powers are irrelevant. They a members of a recognised police force and are accountable through the same procedures a constable is. Anything you tell them has the same data protection, so you know that your details will be handled properly. They can also access other services which random security can't.
Their uniform is also standardised to some extent, via ACPO guidelines. My point is that they don't just make up their uniform and are proper professionals in their role.
Also, PCSOs have more powers than a civillian, they also have one or two powers that constables don't.