Using the Samsung migration tool software was astonishingly easy and pain-free. I used a USB 2 connection to clone the drive so it took a little while (about 3 hours), swapped the SSD for the system hard drive and it just worked!
Then I went and terrified myself for a while as the Samsung Magician was saying that the drive would work better in AHCI mode. I went into the BIOS, changed the drive mode to AHCI (3 options; IDE, RAID and AHCI) but then Windows was blue-screening every time it started up. Also, it was no longer possible to enter the BIOS using the del key! My BIOS is some kind of weird 'Hybrid EFI' thing. I noticed that one of the start messages was saying something like, "only works with disk drives". So I swapped the original system drive back in, was then able to boot into Windows without blue-screening, restarted and then was able to re-enter the BIOS and change the setting back to IDE. Put the SSD back in and decided to leave it well alone from that point on.
The only issue I've found thus far was that I had to re-register the ARC2 software.
The system still sometimes hangs at the BIOS splash screen at start-up though, so it wasn't the drive after all. No idea what's causing that to happen yet.