I am not really interested in the detailed specifications, I am after
reviews from pilots who have used them (comfort, features, weight etc..)
ideally comparing the pro's and con's between the different models.
Never a problem with mine.
I plug them in - they work.
They are comfortable and I like them.
They are reliable.
I don't look beyond that
--
Tony Roberts
PP-ASEL
VFR OTT
Night
Almost Instrument 
Cessna 172H C-GICE