I have a Pogo and I've also used the Boxwave Stylus.
The problem is the capacitive screen is the real limitation. The way the iPad screen reads inputs requires a certain diameter before recognizing them. This inherently limits the level of detail possible. So, all of the styli achieve pretty much the same results. It really comes down to personal preference in relation to the quality and comfort of the stylus, as they all have different designs.
The Pogo has a spongy sort of tip which can lose its shape over time. The stylus is also a bit narrower than a regular pen or pencil, which some people find annoying.
The Boxwave has a rounded rubber tip fastened to the stylus. This seems like it would last longer than the Pogo. It is also shorter and a bit wider.
Overall, if your idea is to take notes, you're probably going to be disappointed no matter what. But for drawing and painting any of these solutions will be adequate.