Somehow I still remembered most of the shell syntax in a book I read about it probably in 2001. Don't ask me ... I don't know how either.
Got bored in about 10 minutes but still, another box checked off!
https://www.pearsonhighered.com/assets/samplechapter/0/2/0/5...
The slowest would be the 11/725, which was a cost-reduced 11/730 that had a reduced clock speed and half of the bus slots filled with epoxy to limit expansion. The 11/725 was so slow that using it was an act of masochism; It was slower than your 11/23+.
Those models were pretty rare though. Even though they were cheaper than an 11/750 the performance drop from the 750 to the 730 was too severe to justify even the reduced cost. If that were all then maybe replacing PDP-11s being used in industrial applications might have saved it but the 730 was still too expensive versus the existing PDP-11 products, and the 725's limited expansion made it less attractive than those same PDP-11 products. The PDP-11 thus outlived both the 725 and the 730.
The PDP series brought us Unix and GNU, and the VAX was the only mainframe capable of competing with IBM. DEC was the largest terminal manufacturer (they made the vt100 and vt220. if you've ever run a terminal emulator, chances are it's emulating one of those or a machine that did). They created CP/M (and by extension DOS). DEC is very well known