The 193 also needs an option for ACV (1930), DC current (1931) and AC current (1930+1931). Without those options it would be less versatile than the more modern 196.
The 196's form factor would make it more convenient for bench use. The 196 has offset compensated ohms which as far as I know the 193 doesn't have, while the 193 can measure AC+DC voltage in addition to AC voltage, while the 196 can only measure the AC component and you have to measure the DC separately and calculate the root of sum of squares. Based on this, I'd prefer the 196.
Their respective user manuals indicate the 196 has better ultimate accuracy, and is a 3,000,000 count readout as opposed to 2,000,000.
Careful, the Keithley 193 (from 1985) is 5.5 digit, 200,000 counts, while only the later 193A, which came out around the same time as the 196, is 6.5 digit, 2,000,000 counts. Looks like they might have used some of the improvements developed for the 196 to upgrade the 193 to also 6.5 digit. The 196 also has a 5.5 digit sibling: the 199 which has the same form factor and most features except offset compensated Ohms.
My advise would be: If you can get the Keithley multimeter for comparably little money and you're prepared to repair/tinker if necessary, go for it. If you want a troublefree daily driver, get something more modern...
I use a 199 (very similar to the 196) as my daily driver for things where the handheld doesn't do well (like monitoring things) and I don't need more than 5.5 digits or functions it doesn't have (diode test and continuity are the ones I miss most). I got them cheap. I find the user interface very easy (just press the button for the function you need), and the display is excellent and readable from pretty much any angle, distance or lighting. Easier to read than a VFD in my opinion, never mind LCD.