In printer shopping for myself, I used these criteria:
SPEED
Yes, actually I could have afforded a new daisy—one of those $450-$1,000 models.
The problem was that most crept along at less than 20 characters per second. That sounds fast, maybe 200 words a minute; it isn’t. You must redo an entire page if you want perfect typing but wish to make one change in material already printed; you can’t just white out the wrong word and stick in the correct one as you can with a typewriter. Often, after completing a supposedly final version, I see many changes I should have made on-screen. Somehow my editing eyes are sharper with paper.
People less fallible than I can make do with 20 characters per second. They get everything printed right the first time.
Then again, if their printing volume is too high, a snaillike printer still will bog them down.
And if they’re using their computer system to store and print notes or records, a faster machine is a must. That’s especially true if you’re churning out nothing but long rows of numbers. If best impressions don’t count, you might consider a high-speed dot matrix capable of more than 150 characters per second—or even 200 or greater.
My Panasonic dot matrix was somewhat of a compromise, with a draft speed advertised at 180 characters per second and a near-letter-quality one of around 33 cps.
WARNING: Please note that advertised speeds may be one-third or more higher than the actual speeds. The advertised speeds may not consider factors such as the time it takes the printer to go from one line to another. This is particularly true the case of unidirectional printers, which print only from left to right rather than in both directions, as do bidirectional printers.
The only real way to judge a printer speed in your application is to try it with your own sample material.