Since I've had a lot of time to think more on Unprepared, I wanted to put down my thoughts on the real problem behind it.
More than the power level, when I was playing gadgets early on, I hated the feeling of helplessness that that card put into me. I usually didn't have the ability to turtle long enough to both invent enough gadgets to stop it from being an issue, and to then spread them out. I'd usually watch as my entire game fell apart because of one card, or I'd have to run a deck that had a few gadgets, rather than a deck with gadgets as a theme.
I came back from one or two GenCon tournaments feeling completely demoralized by one card in the set. I can appreciate that it exists for a reason, but man that card just was a negative play experience, and I'd rather fix those than worry about its absolute power level.
For me, part of the reason it was so negative was that it was easy to slot into any deck, because it did so many things. That's why I'd like to see it have some cost, or some toning down to its ability. I'm not sure, exactly, what it would take.
I will say that a lot of my most negative experiences came from before ASM, so take that into consideration.