So I've tested a few new (to me) 3x3x3 cubes and here are my impressions:
C4+C5: Lockups, that make me crazy, faster compared to C2 (my previous main) and a bit clicky. Overall: not so bad.
Dayan LingYun V2: Very fast, cuts corners well, a few lockups. I like to Play with it but I would not prefer it as my main cube.
GuHong 2: Very fast, good to control, but sometimes lockups.
Zanchi + 48 Edge mod: Similar to GuHong 2, but a bit better, faster and better to control.
ShengShou Wind: Very good for beginners and nice to play with it since it is so silent.
ShuangRen: What the hell.. I cannot image a better cube! This cube is just perfect. It's creamy, good to move, it's like there is no resistance at all, you just move your fingers and cube does what you like. Cut's corners very well! I would recommend everyone to buy it (I have a white one).
Thank you for recommending me the ShuangRen, it's a dream for me, much better than GuHong and Zanchi!
Here is a good review:
http://www.youtube.com/watch?v=MKYhupI5nwM