Make sure that the unit you are looking at has the full life of the battery still on tap. I had bought a FastFind at REI that was a great low price, until I saw the expiration date on the battery showed it was already two years into its useful life. Suddenly not such a bargain, I returned it. I ended up with the ACR and that unit had full battery life available.
Note that this is not a criticism of the unit or the manufacturer but of the amount of time that particular unit had sat on the shelf.
Also check to see if ACR has any rebates — mine did when I bought it, bringing the effective purchase price down to around $200.