Have come across the term IOP in some reviews recently but am at a loss to figure out its meaning?  Anyone care to help?  Thanks.

but the UD also has some alternate definitions.   #3 could well be applicable.

Input/Output Processor?

Mr. Sullivan’s suggestion is most apt, fits with use context in the reviews. Thanks for creativity ( and laughs) regarding the other possibilities.  
“ Illusion of passion” it is!