X4 Dock power supply with T42 --seems to work fine?

[zverg]

On my quest for a more compact power brick for my T42 (for no good reason.. it's not like the original was that small) I have come across the X4 Dock power supply. It's slightly smaller, and only outputs 3.5A instead of the 4.5A that my T42's power supply outputs.

So should this work as flawlessly as it has? I know with Dell there's a few different wattages of power supplies sold, and if you use one that isn't powerful enough the laptop will warn you and do something like lower the clock speed or not charge the battery in order to allow you to use the laptop. My T42 seems to be working without any issue, even after being 100% apart yesterday afternoon. I was installing new screen hinges, saw some dust underneath a corner of the motherboard, and got carried away haha. Pics of that later, don't have my card reader to get them off my phone at work and don't feel like dealing with the slow speed of bluetooth.

Physical differences:
X4 power supply isn't rectangular.. well it basically is, but it has a corner chopped off. On this angled part is where the power cord comes out, and at an angle. The whole surface of the unit is pretty smooth, no ridges like the T4x power supply. The power cord from the brick to the ThinkPad is slightly thinner. I'm guessing a thinner gauge wire since it can only supple 3.5A.

FRU 92P1045 in case anyone needs a replacement power brick. If it works just as well and is slightly smaller, why not?