There is definitely an observable difference. In the most broad terms:
Both types of software feature innovative solutions to problems, have the full range of code quality (from awful, to state of the art), and have slow support.
The biggest difference I see between Open Source Software and Proprietary Software is that the OSS tends to be available long after the availability of the proprietary software from the same era has disappeared.
Another difference - with OSS you are able to review the code and avoid using software that is horribly made, but with proprietary software you often have no way of even knowing what the state of the code looks like. Much software (regardless of license) is duct-taped together, at least with OSS you have the means to verify this for yourself.
If I was going to try to get support for a 10-year-old piece of OSS I would probably have better luck than trying to get support for a 10-year-old piece of proprietary software.
If I was going to try to re-download a piece of software from 15 years ago, I'd probably have a much easier time finding and acquiring OSS compared to finding proprietary software.
So, having said all that - if you needed to pick a solution to use today and you wanted to be able to still get support for it in 10 years, or still use it at all in 15 years, I would think OSS would get you farther. Not all OSS is going to survive, but it seems virtually all proprietary software has a very short life.
Also - what happens to support for proprietary software when the company who made it goes bust (even if it's brand-new). Suddenly you're going from 'commercial support' to 'no support' instead of 'slow support' with OSS.
Now, from a developer's standpoint I will choose OSS licenses for my own work every time, and if I'm going to be using another tool in my work I pretty much only will touch OSS. The reason? A number of times in my career already, the owner of a project I have done work on has come to me with legal paperwork for me to sign stating that 100% of the code I submitted to the codebase I own, and that I accept FULL liability for any claims made against the codebase in the future.
Once you've had to sign a few of those papers you start sweating, double-checking that every plugin, every snippet, every library you used is indeed free for you to use (and sell) in another piece of software you're working on.
Because of this, all of the software I produce is open-source, just so I can be sure I (and everybody else) can easily legally re-use the code in any new projects without having to worry.