For any fan of disruptive consumer technologies, watching Airbnb’s rise has been all sorts of fun.

Since its debut in 2008, the company, based in San Francisco, has booked more than 2 million nights of lodging all over the world. But it’s not a hotel. Instead, it allows people to rent out their entire home or apartment – or just a room or a bed – to others who find Marriott boring or want to see life in a new area as a local would.

Today, Airbnb has about 100,000 listings in 19,000 cities and towns in 192 countries. The company takes a small cut from both host and guest and has a friendly looking website connecting both parties.

For hosts, Airbnb can be a great way to make extra money. Guests can rent family-size lodgings that hotels can’t offer, or they can sleep on a couch and use the savings to eat and drink more richly.

But my hypothesis since the beginning has been that the best use for Airbnb is as a hotel replacement in cities like New York, where rates are generally absurd.

So recently, I took an Airbnb lap of New York City, staying in five places in different neighbourhoods to see how much I could save and what I’d have to put up with to achieve those savings.

I stayed in two one-room studios, one one-bedroom apartment, the second bedroom of a two-bedroom unit and behind a screen in a living room next to a window with an unobstructed view of Lower Manhattan.

Here’s what I learned:

FLAKINESS

Airbnb’s nice-looking booking engine is only as good as the hosts standing behind it. And many don’t bother to keep the calendars on their listing pages up to date. That makes the site’s search-by-date function maddeningly misleading.

For every reservation request for which I got a reply (hosts must decide whether or not to accept your booking; more on that later) for an open date, there was at least one other that yielded a reply telling me that the place was actually unavailable.

Some people didn’t reply at all, and others did days later, which is a problem for anyone travelling soon.

An Airbnb spokesman, Christopher Lukezic, said the company had a sort of flakiness algorithm that recognized and eventually punished such behaviour, taking steps up to and including removal of listings.

It took me a fair bit of work over many days to set up five nights of stays. What I didn’t realize is that many Airbnb users will send out several reservation requests at once; this is fine with the company, and it says its systems will not allow guests (or hosts) to double-book accidentally.

When it comes to the financial transaction, the casualness ends. Airbnb charges you before you check in to deter no-shows. But the hosts don’t get the money until a day or so after your arrival, just in case the lodging is not as advertised.

DISCRIMINATION

Because hosts can reject guest bookings for any reason, you have no way of knowing whether there is truly no room at the inn or whether they find you untrustworthy.

I was turned away by, among others, a teenager renting out his brother’s old room and a family with four children. Did they not like my picture? Or the fact that I was a man travelling alone?

I did start the week with one positive review on my profile from a previous host, which should have helped some. Guests can review hosts, too. (I did not, by the way, mention my affiliation with The New York Times in my Airbnb user profile, and it didn’t come up in conversation during my stays. I did let my hosts all know about my plan to write this column after I checked out.)

CANCELLATIONS

Even after all that work, hosts can (and do) cancel confirmed reservations at the last minute. So can hotels if they are overbooked, but my hunch, given the number of reviews mentioning this, is that it happens at Airbnb more than it does at hotels.

When it does, as it did to me in California several months ago, Airbnb tries to find you another place to stay and may compensate you with a voucher, too.

Hosts can suffer if enough reviewers mention this problem. Airbnb can also penalize them by lowering where they show up in the site’s search results.

SECURITY

Over the summer, Airbnb badly bungled a situation where one of its hosts returned from a trip to find that her home had been ransacked. But potential guests may not feel 100 percent comfortable either.

You may want to book only with hosts who have many positive reviews. That said, you may still find it hard to shake the feeling that there is a stranger in the apartment with you or one with a key somewhere else in town.

CLEANLINESS

The apartment where I stayed in Prospect Heights in Brooklyn smelled reassuringly of bleach. On the Upper West Side of Manhattan, there were a couple of bobby pins strewn on the floor.

In Battery Park City in Lower Manhattan, there were long dark hairs on the toilet seat, but I was willing to let that go because the whole place had such a lovely, girly scent.

And yes, I checked for bedbugs. Nothing doing. But there was a small, live insect on the toilet seat of that Upper West Side studio in the middle of the night and a larger dead one on the floor next to the bed.

COMFORT

There are no brand standards on Airbnb, no heavenly bed or anything like it. I encountered both high thread counts and scratchy sheets.

The best-looking place – that Battery Park City two-bedroom – had the least comfortable mattress. So there’s no predicting what you’ll experience, and reviews from previous guests may not help much.