I was a rabid, rabid OS/2 user. A good friend bought 3.0 the week it came out, showed it to me, and I immediately went out and bought it. Windows 3.1 was a huge step down from Amiga multitasking, but with OS/2 running on my PC, I didn't miss my Amiga as much. The user interfaces were different, but at least the capabilities were similar. When I tried to use Windows 3.1 the way I used my Amiga, I'd crash the system hard very frequently--maybe not once a day, but several times a week. With OS/2, I had maybe three hard crashes that required a reboot. It was nearly as stable as Windows XP SP2 was, but in 1994.
When I worked selling computers at retail, I actually managed to sell OS/2 to a few customers. Especially after IBM let us install OS/2 on one of the in-store Aptivas. I'd just open 16 DOS windows and do a DIR /S C:\ in each of them, then do the same thing on a Windows 3.1 machine. People could watch how badly the 3.1 box crawled, while the OS/2 machine just casually and smoothly juggled all 16 disk-intensive tasks.
I ran OS/2 as my main operating system on my home PCs until well into 1998, and I multi-booted for a long time even after that. I ran 3.0, and upgraded to 4.0 after 4.0 came out. I ran it on several different machines over the years, including a 40 MHz 386, a 486SX2/66 (yes, SX), a Pentium-75, and a Cyrix 6x86MX. The college I attended ran OS/2 on its servers and most of its workstations, and my first non-food, non-retail job was installing network cards, memory, and OS/2 on IBM PC 330s and 350s. My first real, full-time job with benefits was running that network. They'd been running OS/2 since version 0.9. But, sadly, software requirements eventually forced them to migrate to NT. I built the school's first Windows NT 4.0 servers. I don't recall whose job it was to finally shut down the last OS/2 server standing. I argued in favor of running the print servers on OS/2 even after the migration, since its hardware requirements were lower than NT 4 and, frankly, I think the later versions of OS/2 were more stable than NT4 was. But the professor who was in charge of our shop at the time had a bit of an anti-IBM chip on his shoulder so he didn't allow that.
A few years ago, I dug out a 266 MHz P2, loaded it up with a bunch of RAM, and loaded OS/2 4.0 on it. It absolutely screamed. The machine didn't have enough power to run even NT4 decently anymore, but OS/2 turned it into a dream machine. I think I had difficulty tracking down reasonably current builds of Firefox and Openoffice for it, otherwise I probably would have kept it around.
A lot of people badmouth OS/2, but those who actually used it, and who actually ran more than one program at a time with it, liked it. The reason was simple: Nothing else available at the time did what OS/2 did. It provided cheap PCs with real pre-emptive multitasking like an Amiga or a Unix workstation, but you could run your Windows 3.1 applications and your DOS games on it. For that matter, some of the DOS games I liked to play ran faster and smoother under OS/2 than they did under DOS. Windows NT 3.1 and 3.51 could run your Windows 3.1 apps with pre-emptive multitasking, but they didn't have nearly the hardware support OS/2 did, and NT didn't even begin to have OS/2's DOS compatibility. People talked a lot about Windows NT in 1994 and 1995, and used it as an excuse to not use OS/2, but I only ever ran into two people who actually ran NT prior to version 4. A couple of cutting-edge people running NT came and asked me for help when I worked retail when they couldn't get certain pieces of hardware working in NT, but I wasn't able to help them. Funny thing was, in most cases whatever it was they wanted DID work in OS/2, at least to some extent.
OS/2 didn't have nearly the hardware support that Windows 3.1 or Windows 95 had, but if you wanted a true, fully 32-bit OS, it wasn't until version 4 that NT started to pull ahead of OS/2.
If you haven't figured it out yet, I really miss OS/2.