I'll give my two cents...
No OEM ignition is going to be correct for your specific application unless your specific application is that which the OEM ignition was designed for. An example of this would be that the SUGO ignition is designed to be used in conjunction with the COMPLETE RACE KIT. This doesn't mean that good results can't be obtained from an OEM ignition. People have and do get good results from OEM boxes. A SUGO ignition with appropriate set-up is a known route to decent power with a 3xv. Take Mark Jordan and the KR1S for instance, he has stuck with the stock ignition and made a monster of a motor work around that.
I can see the appeal of using a fixed curve box. Less time needed on the dyno, cheaper set up costs, less variables to change. I've nothing against them at all.
I like the programmable ignitions. They do as Warwick mentions cost alot to set up though as you do have to spend a fair bit of time on the dyno dialling them in. Each time you change a component such as a different design of exhaust, ideally you need to go back to the dyno to get the PV and ignition curves dialled in again. Otherwise you aren't getting the full potential of the programmable.
Personally I like seeing what happens on the dyno and what does what, I find it interesting. A programmable is right up my street and that's why I stuck at it with the 3xv when the wiring issue hadn't been sorted.
If you have the time/money/inclination to go to the dyno everytime you make a major set-up change then a programmable is for you.
If not, stick with an OEM box.
That's my simplified view anyway

Dan