I have lately used dynastrip which isnt bad but nowhere as easy to use as preps. I used to think preps was the best you could get till I found Metrix from Litho Technics
LithoTechnics - Metrix, the automatic layout calculator for commercial and gang run printing
Demo movies
Index of /learning/Help Movies
Used JDF import to ApogeeX and its AMAZING!!!!!!!
If you dont have JDF it can make preps templates. It also can print out an Impo preview with all you measurments on it so your printers cant complain (as if they ever do!)
Check it out
Its the future