USB booting has saved me so much trouble.
I've managed to boot from USB using 4 iBooks (300, 466, 466, 500), 2 iMac G4s (both 800), 2 iMac G3s (500 Graphite and 450 Ruby), and 1 Power Mac (G4 350 AGP), and maybe more that I'm forgetting about.
From my experience, all Macs from mid-1999 (Power Mac G4 AGP, slot-load iMacs, all iBooks, Pismo) onwards can boot from USB, but then there seems to be problems again around 2003+ (but I haven't tested enough of these to confirm, since it's not really an era I'm interested in.)
The early new-world Macs (tray-load iMacs, PMG3 B&W, Lombard) cannot boot from USB, I've tried it on all of them.
I always would prefer that my Macs are self-reliant-- i.e. if the HD/SSD failed, I would be able to solve the problem without relying on another Mac. Bootable USB drives and drive cloning software makes this easy, and I'm patient enough to wait for USB 1.1 speeds when transferring data.
I don't care for Firewire, especially since my old iBook and Wallstreet don't have it anyway. As for CDs, I've had too many CD drives die on me to care for that option, either.
Even if it's USB 1.1, I'd rather boot from USB as a backup, and for Macs that can't do it, I use a USB-SSD adapter and test on another Mac...
PS: of course, results may vary. But we should also remember that a lot can go wrong with weird/faulty USB drives, incorrect formatting, and even faulty hubs which don't provide enough power to the device.
I've managed to boot from USB using 4 iBooks (300, 466, 466, 500), 2 iMac G4s (both 800), 2 iMac G3s (500 Graphite and 450 Ruby), and 1 Power Mac (G4 350 AGP), and maybe more that I'm forgetting about.
From my experience, all Macs from mid-1999 (Power Mac G4 AGP, slot-load iMacs, all iBooks, Pismo) onwards can boot from USB, but then there seems to be problems again around 2003+ (but I haven't tested enough of these to confirm, since it's not really an era I'm interested in.)
The early new-world Macs (tray-load iMacs, PMG3 B&W, Lombard) cannot boot from USB, I've tried it on all of them.
I always would prefer that my Macs are self-reliant-- i.e. if the HD/SSD failed, I would be able to solve the problem without relying on another Mac. Bootable USB drives and drive cloning software makes this easy, and I'm patient enough to wait for USB 1.1 speeds when transferring data.
I don't care for Firewire, especially since my old iBook and Wallstreet don't have it anyway. As for CDs, I've had too many CD drives die on me to care for that option, either.
Even if it's USB 1.1, I'd rather boot from USB as a backup, and for Macs that can't do it, I use a USB-SSD adapter and test on another Mac...
PS: of course, results may vary. But we should also remember that a lot can go wrong with weird/faulty USB drives, incorrect formatting, and even faulty hubs which don't provide enough power to the device.