I too would have to say that I fall in love with the person rather than their individual parts.
I've lost my heart in the past to a trans-gendered woman. Sadly, her ultimate lack of libido and a few other issues, that seem to come as standard with Thai ladies, ultimately led to our demise. Took me a long time to get over her though.
Since then I have dabbled mainly with pre-op ladyboys and very much enjoyed the difference. Once again though, there is huge variance in their libido - so, in my opinion, it's as much down to the individual as any reflection on what changes surgery and hormones can make.
Now to muddy the waters even further, I met the most amazingly responsive post-op ladyboy some days ago. This would suggest that it may also depend on which surgeon did the job and how good they are at retaining nerve sensitivity etc.
This lady - who happens to be a total goddess - and I also seem to have a very good rapport/connection outside the bedroom. To cap all that, everyone who has seen her has asked who my gorgeous new girl is. Even my closest mates here in Samui haven't 'twigged' and they know I have a preference. What fun!
Is that the sound of cupid plucking my heart strings again? Sigh...