Ataman bullpups compared to others?

I recently read an article at hard air magazine about the upcoming ataman mb20, which is going to be a pcp bullpup air rifle designed for slug use. Now, although it hasn't been released yet, i've been considering getting a pcp bullpup in .22 for a while now and this seems to be a good deal. Ataman has been around for quite some time now and they have many different bullpup models in their lineup. I was wondering, how do they compare to other popular pcp bullpup rifles in terms of accuracy, durability, ease of use etc?

The other rifles i'm considering are: 

fx wildcat .22

airgun technologies vulcan 2 .22

taipan veteran long .22