My experience is much like yours.  Currently am rather close with three (yup, three) escorts.  I would call these relationships significant (dinners, travel, etc.), but not serious.  In all 3 cases, we reached a point where, in order for the relationship to move forward to a "serious" level, the ladies would have to think in terms of "normal" as opposed to "hooker," and this is very difficult for a woman who's making big bucks doing this.  OK, one of them is in the process of making the switch, but although she's been out of the business for 6 months, I know her mind is still there in terms of being able to go back to it at a moment's notice.  All hookers think about how they will retire and get out of the business, but when the opportunity actually occurs, most will either not recognize it or indeed ignore it.  In my experience, these women want out, but don't have a clue as to how to go about it, particularly if it involves a noticeable falloff in income.  Unfortunately, love is the one element that doesn't seem to enter into the equation, and that's why most escorts will wind up being very lonely and unhappy later on in life.