An easy way for NYC renters to schedule apartment showings

I just rented an apartment in NYC this week and using Naked Apartments and RentHop were great -- forget about Craigslist. Naked Apartments combines duplicate listings which was definitely a helpful feature in my search. This new feature seems really great and helps prevent waiting around for email replies (some brokers are ridiculously fast, some aren't).

Is it very difficult to find a good apartment for rent in NYC? What do people need to know who are unfamiliar with the landscape?

Thinking back to apartment hunting in NYC a few months ago makes me want to vomit. I am never going to do it again, I'd rather leave. I had a lucky break that did not involve using any of these services nor a broker.