Turning a 3/1 into a 3/2 vs a 3/1.5 - What's the Better Play?

[Bob Crane]

The question - is it better to make a big room small by adding a full bath or save some of that floor space and only add a tiny half bath?  

I own a 1500 sq foot ranch built in the 50's in a C+ neighborhood in small town Illinois.  The house is currently a 3/1 with the 1 bath being on the opposite side of the house from the bedrooms.

The front bedroom is 11x14.5.  My plan is to take a portion of that room and make a bathroom (bathroom would land in the same hallway as bedrooms).

The question - Do I turn the bedroom into a 9x11 and make a full bath or still a corner of the room and create a 4x5 tiny half bath (which would salvage some floor space in the bedroom).

The other two bedrooms are 12x14.

I've done some forum searches but couldn't easily find this scenario.