Questions, questions, good
To explain easier, I'll call mine the DIY and the other, the standard.
Stability is perfect for the standard on a flat surface, not that much on a roundish one because the base is a straight rod. The base will be touching in the center and you will not be able to keep both extremes of that rod in touch with your belly at the same time (considering an average belly
). The risk of tilt is there alright. The curvature of the DIY prevents that, therefore, more stability.
On the other hand, you cannot rotate the standard because it does not have an axis to rotate on. The DIY is specifically designed to rotate the ebook wile keeping the supporting part always in place. You can place the ebook sidewards in the standard, but the ebook will not be properly attached and will most likely shift every time you pass page or mive in bed. ANd it can drop. It is never propperly attached actually, since it is just held in place (not fixed) by these two pins, designed to hold paper books. The DIY keeps it fixed in place with two laces. The Reader just can't fall off the stand. You can see all this in the youtube video of the DIY string.
I am not trying to sell anything either (well, maybe I am trying to sell the design right now
). The plans are there for anyone to use and the procedure is quite simple. I tried to get them as accurate and complete as possible so there is no info missing.
The reason why I designed this is mainly to read comfortably when lying sidewards and I couldn't get that with the ones I found for sale. The design turned out to work great in any normal position, though (lying on your back or sitting). And it is specifically designed for the PRS 505, not for paper books of different sizes. You don't need to believe me, but the difference is huge.
But hey, this is just my little contribution. No one is forced to try
The important thing is reading, after all...
Hope this helps