Echoing what some have said I think it depends on your needs. If you want to be mostly un-involved and collect a check, a good property management company is a good way to go. I have worked in the short term rental business for many years. The good companies are dedicated, knowledgeable and typically have good staffs. They are costly but you are getting (hopefully) top notch, dependable service for your money.
Check references for companies in your area. Find a company that has been in business for 5+ years. Read the owner contract carefully. If there is any vague language concerning who pays for what, RUN! It should be spelled out. Things like:
1. who pays for Travel Agents costs (OTA's)?
2. how do they determine maintenance charges (hourly rate - do they add drive time?). Do they have a monthly maintenance program that covers the nickle-and-dime stuff (light bulbs, HVAC filter replacements, minor maintenance). Maintenance typically becomes a 'rub' when you get charged $50 to change a light bulb.
3. Look at their web sites and simulate a booking. Are they tacking on charges to the guest? If so, the homeowner is usually cut out of this revenue stream. It's a way that less scrupulous PM companies soak owners out of revenue. Ask them about additional charges to guests.
4. How sucessful are they at marketing? This is another component that you are paying them for. If they can provide you with 4 or 5 more bookings a year than you would get doing it yourself it makes a difference. They also have knowledge for what to charge in your market. This is valuable. You can figure it out yourself but it takes effort.
5. How do they handle housekeeping? Is it done by employees or do they contract it out? Housekeeping is THE critical component to this business in my opinion. If your place isn't looking great when the guest checks in you are going to get bad reviews.
In all of my years I have come to the conclusion that these companies are all making similar money. They have to to survive as a business. If they charge 10% commission on bookings they are probably making money elsewhere with guest charges and other fees that aren't fully explained when you sign up. If they charge 30% commission you should be getting pretty much everything covered with few or no additional fees.
Another bonus to hiring a professional PM is that they should be providing good accounting information to you. You should have an owner portal that you can log into and get details on revenue and expenses. You should get a direct deposit type service for your monthly income.
These are just some of my random thoughts. I've worked both ways with our rental properties. We like doing it ourselves but it is challenging if you aren't nearby. Having a PM handle things provides peace of mind and minimal hassles. This is not a bad thing.
Good luck!