I recall trying OS/2 2.0 or 2.1 back in the day, coming from a DOS/Win3.11 setup. It seemed to have the same basic features as DOS/Windows but wasn't properly compatible with my existing software. Admittedly, this was before I knew anything about programming. I discovered Linux not much later. It wasn't compatible with anything either, but seemed like a totally different and much more compelling proposition.
I started out with OS/2 v1.1. It had threads, DLLs, multi-tasking, much larger memory space, and from v1.2 a somewhat decent filesystem. Coming from DOS 3.2/Win 2.0 this was an incredible leap, in particular the SDK was amazing compared to the ragtag assembly of info I was used to. The _delta_ between two systems haven't been this large ever since, and I think that is what contributes to the "magic" feeling.
However this also meant a more beefy hardware than the DOS/Windows 3.x combo.
I was mostly a kid with a huge stack of PC games I'd play, and OS/2 was a better launcher for many (but not all) of them than DOS/Windows. I was "dual booting" OS/2 WARP and DOS/Windows, but because of my gaming habits it was more like quintuple booting because I had a long boot menu with I want to say 4 to 7 different combinations of AUTOEXEC.BAT/CONFIG.SYS settings depending on type of game I intended to play or if I was going to use a Windows app or something else, then one OS/2 WARP boot option.
A bunch of Windows apps (many of which ran better, even) and even some games I recall I started launching from OS/2 WARP instead of DOS/Windows, making the first boot choice of the day a lot easier. (Though I don't remember being able to delete most of the other combinations, still had to reboot for certain games and Windows apps that needed more RAM than what OS/2 left for applications. OS/2's biggest problem at the time was a huge RAM footprint compared to Win3.11, much less DOS micro-tuned with AUTOEXEC.BAT/CONFIG.SYS low footprints for specific driver combos.)
It was also capable of sharing Mainframe printers using a real null-printer-driver, which was not possible on Windows NT3.51 or NT4.0. Windows always messed with the Mainframe codes that it could not understand.
It was also easy to set up OS/2 as a gateway between different network hardware and protocols (Token Ring to Ethernet, or NetBios to IPX/SPX, ...)
It had REXX!
Computers were far more crashy in those days, but OS/2 crashed far less often than Windows or even DOS did. And sometimes when a program crashed on OS/2, it only killed itself; it didn't take down the whole machine, so you had a chance to save your work in other programs before rebooting.
It also either was, or felt like it was, very very fast. Windows felt like a laggy VNC connection. GEM and the rest weren't much better speed-wise than GEOS on a Commodore 64.
The only stability gotcha was when some OS/2 PM application hung the input queue and then the whole of PM became unresponsive. The base OS continued running fine but PM was then unusable.
Of course it had limitations of its own, I don't think you could any DOS/4GW games. Linux Installation seems simple compared to installing OS/2. I had to go through some sort of pre-installation guide which was printed on a separate paper and not part of the official manual. Also dual boot was meant literally: you booted into OS/2 and then you could "exit" into Windows. Back in DOS/Windows there was a command to do this the other way around. One time I didn't do this for half a year and was really anxious if my setup would make it...
Downloading a file via Zmodem was mostly a single task thing.
The Windows of the day could to the latter, but not the former.
OS/2 on my 8mb 386sx could do both AND have a clock up, and play solitaire, and have another terminal window open.
It took a bit to get there, and there was swapping while everything loaded, but it was true pre-emptive multitasking, while still maintaining the highly time critical I/O stuff that Windows couldn't touch.
Back in that time period tech specs, and tech details really dominated a lot of "computers" discussion. I feel like that has kinda changed as far as the larger world goes (even if on HN tech specs are still relevant). Does an every day user want to use it? was less of a question for enthusiasts.
People today don't realize how much time was spent formatting floppy disks, and how slow the process could be. So slow that eventually companies started selling pre-formatted disks and charging extra for them.
OS/2 could give you back hours of productivity each month simply because you could do something else while formatting a disk.