I've had Compustar on two cars now, both systems were fairly reliable but my issue with them were the way the remotes interfaced with the car. They were slow to react. The alarm could be going off and I could be standing right next to the car and I'd have to push the disarm button several times before the car would react to it. It would flash the antenna button as though it couldn't find the car.
All Compustars do this. There was nothing wrong with your units. If your alarm goes off you can't shut it off until after the "third" tone in the alarm sequence. So it's only about 15 seconds. Before that time you could frantically push any buttons you please on the remote and it wouldn't do anything. I can tell you didn't read your manual.
Of the many alarm/starters I installed I recommend Compustar. Brain/wiring aside the remotes on the DEI stuff are terrible.