Iron Cross Trainers?

I'm wondering if anyone has  experimented with these different designs.  Im wondering if one has an advantage over the other?  Any thoughts?

 

 

These http://ringtraining.com/store/elitestrengthtrainer.html

 

or

 

These http://www.gymsupply.com/ironcross.aspx

https://www.gymnasticbodies.com/forum/topic/12654-are-iron-cross-trainers-helpful/

https://www.gymnasticbodies.com/forum/topic/109-iron-cross-trainer/

Not much to say that isn't already said in those threads. Cross trainers are a fun toy, but there's probably more useful things you could spend your money on. 

I use a cable cross machine in the weight lifting gym to simulate the iron cross exercise. Bloody fun! I do several sets of six. I do as many sets as I can until my arms are dead.