[BRLTTY] Reliable braille display hardware?

[Jason White]

I have two 40-cell braille displays, one of which is only partly 
functional due to multiple hardware problems with both cells and the 
command keys, and the second of which is not functional at all. The 
second display is a Baum SuperVario 40 from the mid 2000s, parts for 
which aren't available anymore. In the best case scenario, the issue is 
only with the battery, which can be replaced.

I'm investigating and considering my options. One of the options would 
be to buy a new display.

In the current market, which manufacturers are producing the most 
reliable and long-lasting hardware, so far as is known? If I make a 
purchase, I want it to last for a long time.

I think BRLTTY compatibility can be assumed for most, if not all current 
devices.