Hope these threads help. The first one is a poll on the HKS and Greddy Boost Controllers, but has no mention of the Apexi one, if that matters. The second thread talks about different turbo timers. If you want straight up opinions, put a poll up for people to vote on.
I have a Greddy FATT (timer) and Greddy ProFec B Spec II. Most of the new boost controllers are great, HKS, Greddy, etc.. all are as good as the user and their ability to set it up correctly. As far as a turbo timer is concern, if my car did not come with one I would not have wasted the money on it, all you have to do is drive like a sane person for the last 5 min of your drive and you have effectively cooled down the car, if your at the track just let it idle and pop the hood.
I dont even use my turbo timer, i set it for 10 sec, the only plus I can say about my Greddy FATT is the voltage and other function it has.