well, by technical, i just mean has anyone taken some time to really give the buttons a comparison to happs buttons. 
g~
I hadn't seen one =P But I wonder why you'd need one. As long as you understand that:
A. the joysticks are similiar in feel/design to a happs super
B. The buttons are a little short with max 3/4" thick cp mounting
C. They are super reasonably priced
D. They are a little cheezier/chinsier, yet are still "arcade quality" but should be fine in a home environment. think of them as k-mart or walmart brand with happs being nikes... =P
If you have decided on all black, cheap, and supers-esque style joysticks on a 3/4" or less CP ...there's not much more to research.
The big selling factor is that they are the cheapest option out there... they aren't the best... but they are perfectly usable.
I will try and find a review(s) on the standard x-arcade unit which uses the same sticks and buttons to see if they compared 'em to regular happs sticks/buttons.... and post 'em here for ya... unless someone beats me to it.
Rampy