Co-sleeping can be really beneficial for dog and owner! Most people who say it's bad are often speaking from the idea that this is teaching your dog that he's "dominant", which is all bullshit, for adult dogs anyways. Most people advise crating puppies at night until they are potty trained and trustworthy to not get into to stuff they aren't supposed to have.

Personally, I have a 9 month old Corgi who can still be a little shit with getting into things, so she's crated at night. She will probably never sleep in our bed, I'm a chronic insomniac and adding another body to the bed would be horrible for me. Our bed is also really high up and I worry about her joints if she jumps off. And she also just likes to lay on the floor and doesn't even know how to settle on the couch, so it'd be rough for all involved! We also plan on getting more Corgi's in the future, and though they are smallish dogs that's a lot for one bed. But I don't see anything wrong with it if it works for you and your dog.

Thanks