It’s funny you mention that. Here’s a random Guitar Center facepalm moment that’s relevant.
I bought a Laney TI100 (Iommi) amp used from GC some years ago. It showed up (actually packed well), but what they neglected to tell me was that it was a European model with an external transformer. Sounded good, I enjoyed it. Decided I didn’t want to always fool with the step down transformer, so I returned it and tracked down a domestic model.
I’m sure you know where this is going. Plugged in, tried it out...just didn’t enjoy it as much as the one with the step down transformer, haha. Sold it, haven’t tried another one since. Go figure.