Perhaps I did not give enough details in my first post...or maybe you guys just need to lay off (haha, see, I'm being assertive!)
Ha, point taken and agreed.

Glad all is okay. I don't ask for reviews but got given some crappy ones (about how I'm fat and live in a pigsty) quite early on. My AW feedback, where clients know that you can give them feedback in return, has been 100% ridiculously glowingly positive. I'm not sure if you said you advertise on AW? It's a pretty yucky site but a lot of my clients come from there - if you maintain a nice profile without the words "cum" "guzzling" or "slut" on it, then it's easy to weed out the morons and only see better clients. I think it might even be more likely that the clients I get from there have a better understanding of the transactional side of this work so are much less likely to be strange and over-attached (possibly due to over-exposure to those aforementioned words), too. But no single method is perfect so yes, like has been said by everyone all over this site, different things work for different people.
I wouldn't ask a needy/clingy client for a review unless I wanted to get rid of him. Can you imagine the irritating matyrdom you'd inspire in him?! He'd drag himself home, collapse in front of his laptop, tears dribbling down his face -
she doesn't love me, she only wants me for a review! Maudlin music in the background, definitely a thunderstorm outside. Such melodrama would probably be extremely secretly enjoyable for the over-emotional type of client but it's unlikely that he's self-aware enough to know this. It would probably also trigger him to start Level 2 of Emotional Manipulation (including sorrowful poems to be sent to object of desire, plus daily moping, and talking about her on online forums to other punters and using lots of these emoticons:

) so you have to be ready for that.
Anyway, I'd say the best clients to ask for a review from would be the cheerful ones who clearly have no problems accepting the absurdity of life in general, let alone of the sex industry, in good humour. I can tell these ones because I love them and they always end up getting free time from me.

Do you have any of these? If so, just be frank with them and ask as they almost definitely won't be offended, they'll probably just be happy to help you out in exchange for having such a lovely time with you!