i have used ccc over and over and have never had a problem of any kind. the price is right, and it does just what they say it will. and i have never heard of any of these other apps. even macaddict mag has talked about using ccc for backups.
btw, if you put that 250gig drive on the onboard ide controller, you will only be able to use about 132gig of it. to get the whole 250gig, you will need to buy a pci ide controller card to connect the drive to. thats wht i did. i got a new drive, put it on a pci card, used ccc to make an exsact copy of my drive, booted to it, and never could tell the difference. then after a week or so, i finially got around to erasing the other drive.
Digital Audio G4/1.467ghz, 1.5gig ram, 16x Superdrive, 256mb DDR3 AGP 6800GS, zip, 2x500gig raid0 for 1tb on sonnet tempo trio, 10.5.4