For those who used it back in the day, what was it like to use Windows NT 3.1 (or 3.5/3.51)? What did you view its pros and cons to be vs., say, the consumer version of Windows 3.1, or heck, against OS/2 for multitasking/stability?
The user experience on NT 3.1 was very much the same as Windows 3.1. In fact you might not even notice during a casual use of it. Here is a web site that shows a number of screen images of NT 3.1 to give you a taste of it:
OS/2, especially the earliest versions clearly showed the similar roots with NT. That same site has OS/2 v1.1 images here:
Both NT 3.1 and OS/2 were significantly more stable than the standard consumer versions of Windows until the introduction of Windows 2000 which eliminated the MS-DOS foundation and merged the NT and non-NT Windows product lines.
NT 3.1 was the first version of Windows I ever used. As far as I recall, I was using it on some 60 MHz Pentium and on a DECpc AXP 150 ("Jensen"). I worked for DEC at the time, and was working on an NT-based project. My experience is from the viewpoint of a programmer who was new to both Windows and to PCs (in fact, it was only the emergence of NT that persuaded me to move off VMS).
I subsequently and briefly used Windows for Workgroups 3.11 at home (approximately speaking, Windows 3.1 with networking and 32-bit disk drivers/file system). I upgraded the home system to NT as soon as I could scrounge some spare SCSI disks from work :-)
The UI was similar on both -- this of course is why the first version of NT was called "version 3.1". However, NT was streets ahead for not-locking-up, for having a usable not-DOS command line, for having a flat memory model, and so on; all virtues a programmer could appreciate.
NT 3.1 was a little slow and needed a lot of memory (16MB was the sensible minimum). NT 3.5 made things a little better, and natural technical evolution soon made 16MB seem not large.
One trouble with NT 3.1 was the usual problem with new systems: application availability. Many programs were still 16-bit Windows apps, running under WoW (Windows on Windows, the 16-bit Windows subsystem). I think MS Office might have been in that category at first.
NT provided useful tools for getting out of trouble - the control set indirection, coupled with last-known-good. The registry was a good thing, providing a simple hierarchical configuration tree (though I'd agree it has not scaled well by the 21st century). The service controller was essential for the programming I wanted to do -- one thing that always annoyed me about Windows was its apparent belief that there was always someone sitting in front of its screen.
NT on the Jensen was no faster than the Pentium, despite the faster Alpha processor (150MHz). Some of that was the design of the Jensen itself, some was down to having to run x86 apps under emulation. I preferred to use the Pentium. 32-bit NT on the Alpha sadly proved to be a dead end.