Compresser for master bus (Hardware)

I know theres a lot of threads out here about compressors on the master bus.. But I haven't seen any
"new" thread.. But a lot of discussion from like 2008-2009 .. So now its time again.. ;)

Im going to buy a new "mastering compressor" for my dance/house/trance productions and I don't
really know witch one..

I have checked this ones out..

*GEM AUDIO LABS - PRECEPTOR
*MANELY - VARIABLE MU MASTERING VERSION
*THERMIONIC CULTURE - THE PHOENIX (SC COMPRESSOR)
*PENDULUM AUDIO - OCL-2

Please give me some feedback about these ones..

THANX ALOT! :)