Beta reading is quite different to sensitivity reading, in my mind. In sensitivity reading, the writer is looking to make sure that they've represented minorities correctly, and haven't done anything that might be insensitive or contribute to the terrible misrepresentation of that particular community. If you have any minorities in your manuscript at all, I cannot, CANNOT recommend sensitivity readers enough. They're important if you care about people at all. They'll let you know if you've miss-stepped, and you can fix it.
Beta readers are somewhat broader than that. They're there, should you choose, to make sure that your overall story makes sense, that your characters remain, well, in character, that your timeline isn't all screwy and so forth. They're not necessarily focused on the representation of any particular community (though that is not necessarily out of their purview, either).
They are there to provide constructive criticism of your manuscript, to make you a better writer, and make your manuscript the best it possibly can be before it's sent off to any editors, acquisitions or otherwise.
What beta readers should not do is tear you down, offer criticism with barbs, provide you with nothing more than simple statements about any issues they have with your work, and, perhaps more importantly, they shouldn't rewrite your stuff to suit them.
Choose your readers carefully. I've had a couple of bad ones, and they can do a great deal of damage, both to your manuscript and to you, personally. It might take a bit of fishing and testing to find the beta readers you trust to handle your manuscript with respect, but also challenge you to become a better writer. That trial and error, however, is definitely worth it.
I would not be half the writer I am without my beta readers. I owe them so very much.
So, writers, find thyselves a beta reader - preferably more than one. Three, at minimum. It's scary sharing your work, and opening it up for criticism, but it will help you so very much.
Next time, I'll talk about my experience with being a beta reader, and some dos and don'ts that I personally abide by.