To me, it's not a good comparison to look at a pc/laptop based system vs. the stand-alone Peake tool. Software systems can provide varying levels of bi-directional communication, programming, real-time data, etc... - but at the cost of convenience. You need a functional laptop, cables, interfaces, and software you can trust. Even then, most generic systems will not read the BMW factory codes, so you're at that disadvantage.
The Peake tool is a one-shot deal. Plug it in, read the factory codes, reset the light, unplug it and move on. No boot time, no clean up - you can carry the tool in the glove box, etc...
If you have little or no need for the extended functions a software system can offer, there is no need to consider that option.
The only fair comparison would be a plug-and-play OBDII tool vs. the Peake tool. Identical in simplicity, but one offers you accurate codes that apply to your vehicle, one offers generic codes that are watered down to work on various platforms. Similar in price, but not in results. Peake wins hands down.