Is the Allison/Crane one the one that took over the LED/slot plate/photo-receiver design from the old Luminition? I had one of those set-ups for almost 10 years and never even had to look at it twice. Great unit.
As to the Pertronics, I use them when I have to, they're a heck of a lot better than points. Install them once, carefully following the instructions, then you almost never have to touch them again.
As a matter of personal preference, though, I prefer the points eliminator that Comp-u-fire sells. Same effect as the Pertronics, just a points eliminator that's all contained in the dist, but I like their execution better. With the Pertronics there's a collar that goes around the dist shaft and the trigger unit reads against the outside edge. The Comp-u-fire uses a disc instead, that passes over the top of the sensor. The magnets are about the same size and strength in both units, but due to the larger arc the disc affords I like to think it gives a quicker spark than the Pertronics. I should check dwell sometime and check, come to think of it. It's also a little easier to get mounted, in my opinion, and a bit more forgiving of a sloppy distributor.
Most VW places sell them along side the pertronics, and here recently they've started carrying an imported Pertronics knock-off called the "Mag-Fire" that's usually about $30-35. I got one to try, looks like a Rertronics, but haven't had anything to put it in yet. At that price it's almost cheaper than a good set of points. Come to think of it, by the time you add in the condensor, it's a coin toss.