I have stayed at a bunch of places in Ocean City, Maryland over the years. Your question caught my attention because I've also been considering staying at Ocean City, New Jersey. I've never been there before, and I'm not sure if I want to switch vacation spots. I love OCM because of the beautiful beach and the boardwalk.
I have been reading reviews of hotels on tripadvisor.com and that has been helpful. You definitely should check that out. But what I've really noticed is that every hotel has rave reviews as well as terrible reviews! I had a friend who spent over 400 dollars a night last summer at the Holiday Inn (on the boardwalk at 17th Street in OCM). The pools and location were great! But, she said she wasn't that impressed with her room. She thought it should be a better room for how much they charge. I didn't personally get to see the room myself, but it looks nice to me in the brochures.
I've stayed at places where the brochures / virtual tours make the hotel look beautiful. But then when you get there, everything smells musty and seems worn. I've come to the conclusion that no matter where you stay at the beach, there's going to be some signs or wear and tear.
Here's one more thing that I learned from tripadvisor.com....... some people don't make reservations ahead of time. They drive to OCM, go to a hotel that they're interested in, and then ask to see the room before paying for it. If they like the room, they pay and stay. I like to plan ahead, so that would be hard for me to do.......but it sounds like it has worked well for people in the past.