The 3x3x5 turns very well, the thin layers give nearly the same feeling as "normal" ones. Of course "vertical" turns (as R, L) are a little bit rougher, because of the complexer mechanism. I never had the feeling, that a piece could pop out. The cube looks very stable and also the outer corners keep in place. They are not to tight, not too loose - just perfectly adjusted. And they are lying flat on the other layers, so there is no space between the top corners and the second layer. The puzzle has still some slight problems with bubbles under the sticker, but I found this tolerable for the moment, especially considering, that I got a second set of stickers for it. Jason already offered me to fix this even before the puzzle arrived! Personally I would prefer, if the sticker corners are a rounded a little bit more, but this is more my personal taste.
Overall a very recommendable puzzle.
Size: edge length 5.8cm, height of the smaller pieces 0.9cm