I run the Crane, MSD 6AL and the MSD Digital 6. The Crane is a nice box, but I prefer the MSD setups. As I said, the Crane is nice, BUT the MSD has always worked better for me.
Of all of them, I like the Digital 6 the best, but it carries a higher price. The Crane and the 6AL performed the same, but Crane coils, IMHO, are not near as good. If installed in a tight area, the 6AL "pills" are easier to change then the dials on the Crane. In my case, there was not a lot of room for the screw driver.
If you buy either the Crane and the 6AL I doubt you will know the difference. If the 6AL ever fails, MSD replaces it for less than $50. Not sure if Crane will do the same.
IMHO the Digital 6 is the hands down winner. I picked up about 2 tenths and have a smoother idle and rev limiter than before.
1992 Firebird 355/Six Speed (Soon to be LT1)
1991 RS 350 / 700-R4
1987 Toyota Pickup 383 / 500 + HP 10.963 @ 119.95 Slicks / 11.997 @ 114.23 Radials
"Speed KILLS, so drive a FORD and live forever!"
Member of the "unwanted" 3rd Gen group.