Unisys Clearpath running OS2200 on the 2200 node: It is the Rolls-Royce of computers. Elegant, secure, trustworthy. It is the mainframe that Harrod's would sell to one.
Early in my IT life I was forcibly indoctrinated to then Sperry 1100 series computers, and never looked back. In the 1990s an IBM DBA asked me if we had a disc failure during the online day how much data would be lost after recovery, and I didn't understand the question. Didn't all mainframe computers offer step recovery that made such events a simple matter of replacing the hardware and typing "RECOVER TO NOW"?
You know, if you bought an airline ticket anywhere in the world in the early 90s, there was a better than 85% chance that your transaction was passed through Unisys hardware and software somewhere along the route.
Wonderful hardware, great OS, robust software that worked (if you didn't count their execrable RDBMS engine: SQL 2.0 compliant my left buttock). Them were the days.
Yoked to Unisys's legendary zero powers of strategic vision and nil marketing accumen, how could they fail?