I've got an old Tiller Master on my Tartan 30 (and a spare). I've had to have it repaired once - the original designer of the unit was working for Moonlight Marine at the time, but may no longer be there. There are no buttons for 'auto-tack' or 'swerve R/L', and it won't handle 6' seas on the quarter - but it handles 90% of conditions.
I suspect the old Tiller Master was designed to do a certain job, and was phased out when it became non-competitive with newer units designed to a price point. Agree that you get what you pay for. But with so many customers shopping by price point, the cheap units soon become all that's available.