Gulliver is right, if you compare a real PAL machine between an NTSC one in PAL mode, the faster oscillator noticeably affects games and demos.
I'd take 2 PAL units. After dealing with the big expanded machines and all the headaches over the last years, I really lost a lot of interest. (Like WHDLoad on '060's - most games ruined with access faults halfway through.) A NOS PAL A1200 with a Blizz 1230, MK2 Indi and 3.1 sounds just about perfect!
