IMHO, To me, GFE doesn't necessarily equate to the lady topping or bottoming. Rather, a GFE is about the established mood for the encounter. To be GFE, I like the kissing, cuddling, and caressing before the main event.

GFE means the same thing with ts girls as GG. But...as someone who has seen a lot of ts girls who advertise GFE it's definitely true they tend to be bottoms more often than not.

for me

topping or bottoming has nothing to do with gfe, it is the other stuff that makes it gfe

kissing
caressing
talking
stroking and snuggling
no rush
all the other stuff that makes the fucking all the better

GFE means:

That the girl comes over and cleans my place a bit, makes me some food, then complains for a while because I never call her, then we have a quickie on the couch while we watch Game of Thrones, then I fall asleep and she goes home. Perfect GFE.

So glad you ask

And although I have to say I like timotl's answer the best, here's mine. From a heterosexual  male perspective, and paying for it to boot, GFE means full service, tongue kissing, with the lady agreeing to bottom, no ifs, ands or buts. If thats not whats in the cards, she should not advertise as such, period. I don't buy any of the arguments that the switch GFE, where the TS is the top qualifies, that should be a separate category from GFE, IMHO.

I stopped seeing TS providers a few years ago since I never got the GFE I was looking for.

For me, a TS GFE would include: kissing, mutual BBBJ and DATO, me topping her, MSOG, and finally, a loving girlfriend attitude. Her topping me isn't necessary to make it a GFE, but doesn't preclude it either.

who do not believe topping precludes a GFE classification.  DFK'ing with plenty of mutual intimacy and mutually being turned on merits a GFE classification.  Until recently I wasn't a big fan of providers summing, but to me it shows that I helped turn them on which makes me feel good about our session.

My opinion is that the chemistry makes it GFE not what acts are performed.
I believe GFE means the session flows without speed bumps or road blocks. If I offer a kiss, and she counter offers with no or a conditional yes = Not GFE.  
I prefer a date without road blocks and try to have the conversation about preferences (Top, Bottom, Verse) on the first call. If the girl tells me she is only a top AND I decide to see her, I'm not going to ask her to bottom when we meet.  
For me, chemistry means the girl is visibly turned on (boner), willing to go with the flow, and she matches and anticipates my chess moves. If a girl does something I like/want before I even ask for it, she's won me over. But if I hear "no" or "I don't do that" especially if it's something she just let me do to her, then provider = Not GFE

That makes GFE for me.  If I'm being topped, it's just part of the Trans GFE for me.

Pegging?

It's really not that uncommon for even a gg to peg their boyfriend if he's open to the idea.  Some relationships have a more dominant female partner, but that doesn't make such a woman "not a girlfriend".

I agree with the general consensus of GFE being more a matter of chemistry and a lack of hesitation or conditional/negative responses.  Whether the provider tops or bottoms is really more of a preference.  Relationships can be nontraditional, but they cannot be impersonal.

For me I think GFE has a lot of parts to it including, kissing with tongue, hugging, mutual BBBJ, mutual DATO, if both are into it, mutual top and bottom. As long as I know all of these are available I feel the whole experience is going to be great. There are times I may want to just top or bottom but as long as the option is there everything is good. After all, one would do most, if not all, of these with their GF, thus the term.

As far as wanting a TS provider to cum is all part of the reason I see TS providers. I try to set my visits by when she is most likely to cum. Either first appointment of the day or last depending on how busy her schedule may be. For me its about pleasing her.

There is nothing worse than asking if she can cum, she says yes then gives an excuse as to why she can't.

gfe is state of mind thing, not play specific

how i usually describe gfe to clients (beyond the baseline that it should never feel like a service after the financial terms are agreed upon). its whatever a gf that's truly into you (in an idyllic sense) would do with you. that could mean being the assertive top during a sesh or an equal play partner during a roll in the hay afternoon delight sesh. its a state of mind thing imho, no matter what the play involved is. xoxo k

Let me add a new dimension to the GFE discussion which Sasha kicked off--even though my comment is not really responsive to her question.  As far as I'm concerned, a satisfying GFE involves much more than sex.  (OK, I can see a lot of you rolling your eyes.  But I will forge ahead, even at the risk of being dismissed as sappy and naive.)  To me, a true GFE requires doing my best to understand and appreciate the human being I am with -- to connect with her, and not only in the physical sense.  I want to learn what she likes and dislikes, what her hopes are for the future, what her most important memories are, what she fears, what she values, what she believes in.  I have no doubt that many providers would consider this attitude to be a threat to their privacy, and I completely understand that not all providers would be responsive.  I also understand that a short, one-time encounter does not provide much scope for this sort of exercise.  But this is an essential component of my GFE ideal.  (And sure, the sex is great, too.)        

To me it is a mixture of chemistry and certain acts.  I need to click with someone and their has to be DFK.  If there is no DFK it's a mood killer to me.  If there is the experience should naturally evolve into passion which is what gfe is to me.