At $450 I'd buy that rifle.
As for the 220 Swift, it's an awesome cartridge. My own 220 is a pre-64 Model 70 with a 4-12 scope on it, accurate but light enough for walking around. I also have a 22-250 in a very heavy Savage target rifle with a 6-18 scope, way too heavy for walking around but a little more accurate. As far as performance on varmints goes they are peas in a pod, you couldn't tell one from the other. Both have slow twist barrels and I'm shooting light bullets in both. I wouldn't worry much about the twist rate myself, even with slow twist limiting you to lighter bullets the Swift has plenty of range and energy for most any kind of varmint hunting. If you do get a 220 I'd recommend hand loading for sure but really I'd highly recommend hand loading anyway, it's fun and you get the most out of your rifles.