I was looking for something to make the new 4E combat both more lethal and a bit quicker. This product serves that purpose nicely. It overlays onto the existing 4E system with little adjustment. Beware, if using this be sure you have a strong healer in the group (if you don't travel with a cleric you are crazy, IMO). One of the other benefits of this system is that it also makes powers and feats that cancel out critical hits (such as Armor of Bahamut) MUCH more useful. It also raises the stakes a bit on those Opportunity attacks! I could regale you with tales of the characters in our group one-punching monsters and pulling their bacon out of the fire in the process. Suffice it to say that combat is a bit more nail-biting and when that natural 20 does come up, it is a LOT more exciting. Pick it up, you won't be dissapointed.