Since no one else has responded, I'll add my 2 cents. You will certainly want the ability to retard ignition timing at higher boost levels. As long as you are buying some device to accomplish that, then it couldn't hurt to have the ability to give the coil a little more dwell time. I've never used one of these magic ignition boxes, but I do suggest that you be wary of marketing claims. You just want the ability to retard timing with boost and a strong enough spark to ignite mixture with higher cylinder pressures. Anything more than that will give minor gains. I went right to the Megasquirt, which just has cheap ignition transistors the size of a fingernail. A little extra dwell is all it took to light off the mixture at higher boost (stock coil and NGK copper plugs). You don't need a big controller with multiple spark events and super high voltages.

Corbin
'97 GSX dressed like a '95 ESi