Just my two cents.
I have used the swap HDD method in the past. In fact the system is still in use with the HDD kits still in it, but one bad swap and one lost drive means I don't swap HDD anymore. I have also used a switch box and two systems, but PS/2 mice don't like being switched back and forth between systems. I now have a duel boot. My first one, and so far it works well.
Part of the fun is trying new things, and thats how I found my way here to a Linux Forum