You are correct that the Pro V1 is technically softer than the Pro V1x.   

However, feel (or perceived softness for some) sensitivity varies widely from golfer to golfer.   It is player-dependent, as different players perceive feel differently.  Some may identify feel based upon drives,  others on full iron shots, others on short game pitches and chips, and others on putts.  Because of this, feel (or softness in some cases) is difficult to measure.  It could be the cover hardness, the compression or the overall construction that impacts the golfer's perception of feel. 

The general differences between the two golf ball models can be broken down by: 

Pro V1:  Large and fast core with thin ionomeric casing layer and high performance urethane elastomer cover.  Provides the best scoring performance for all golfers, and has very soft feel. 

Pro V1x:  Soft center, high energy dual core with ionomeric casing layer and high performance urethane elastomer cover.  Provides Pro V1-like performance with low, long game spin and higher flight.