A whole lot depends on the installer. I have two of them.
They are what I call cable car systems. A total of eight steel cables move the unit in and out (4 each way) and so long as all the holes lines up properly (where needed) they should give you many decades of trouble free service.. IF the holes do not line up they can wear out a cable fairly fast and depending on where it breaks it can be a witch to replace (mine was but I got 'er done) check for that and modify hole if needed.
on Accu-Slide the power unit (motor) will either be above the slide in the fixed header or below it (normally above) you need to remove a fascia board to access.
There are eight adjustment bolt/nuts and they may have jam nuts on 'em.. On mine not all were properly jamed so one came off, check them
IF the motor fails a common electric drill with a quarter inch hex flexible extension (this is commonly used with screwdriver bits) can do the job.. The motor shaft is designed to accept this as a driver.
Controller is the same as Kwikee/Atwood/A&E/Dometic/Power gear use.. that is it is a current sensor..there are not limit switches to go bad.. Just the current sernsor.. When current spikes it shuts off
This can be a PITA (Pain in the anatomy) as it may take multiple tries to get 'er all the way in or out.
But basicaly.. I like them better than my power gear slide.
Home is where I park it!