A provider and client have set a date, had the date, and now client wants to gain access to P411. He chooses 2 providers to be his references and requests their OK's. The client is semi new to the hobby, but has a few reviews under his belt. The client utters nothing about passing along a review for the provider.  

If he is an established reviewer or is building his review base, he'll do one anyway.  If he does not write reviews, he won't even if you ask.

careful that you're not manipulating, but its a business, and there is no free lunch.  Asking for a review is a reasonable and businesslike quid pro quo for the P411 okay, IMO.  As you say, there should not be a suggestion that the review has to be a certain score, and/or positive.  That would be the risk the provider would have to take in asking for the review, but most that have been in the game for awhile can tell by the vibe when the guy is leaving whether or not he enjoyed himself.

Much like "I will give you a whitelist for a positive review" both are considered review manipulation and technically could get you de-listed.

I have never asked anyone for a review. I don't even mention it prior to, during, or after the date.

being asked for a review when I've decided not to do one. The service may have been great but if you showed up late and a bit drunk, I don't give a shit, I'd have to include those things in your review. That's why I don't want to write one because anything negative might turn a few guys away and end up hurting you. Explaining why you were late in a review won't help because just being late gets you on several DNS lists. I'll offer to write one if I can. The P411 OK's and reviews are two separate things. I'd be pissed if you gave me the impression that getting a P411 OK was tied to doing a review for you. I had a provider PM recently and she demanded that I write "her" a review because she "deserved" it. She's still waiting and will be - forever.

There is nothing wrong with asking a client for a review. I don't review every time I meet someone, but I certainly do if asked.

assuming of course you can OK him in good conscience.

I do agree that accepting a P411 OK request is at the discretion of the provider, but if the client was safe and respectful, as GaGambler mentioned, then there should be no reason not to accept the request REGARDLESS of whether a review is involved. Delaying the OK until a review is posted or making the OK even seem contingent on the review is NOT good practice. All of my OK's have come before my reviews are posted and I typically don't even mention I will write a review until the review is posted.

definitely report you to P411. It is not an exchange..

don't do research on the ladies you see and they have a habit of showing up drunk or late or both? And here I thought, based on your fan club, you were a true expert in this field. Shame on me.

My first three escorts never asked for a review.  

While I do agree that few girls have asked me for reviews, I think you are betraying your fellow mongers for refusing to write anything but a positive review.  Maybe you'll learn when you see a girl with all positive reviews who's a total rip off.  I get it that writing a negative review can have repercussions.  If you're worried about that, review her under your alias.  This alias will do that, if needed.  My handle will only write positive ones.  See how that works?
Also, if you expect OTC time for writing a review, she'd better know that up front.  But TER frowns (as it should) on bargaining a reduced rate (cuz that's what it really is) for a positive review.
It's called a pay-off.
Based on this post I'd bet there are a few gals out there who won't see you now.  Another good argument for an alias.

No, it was just a general comment about the ying and yank of precise clock watching.  None of my first have had an issue with time, and I've gone over twice (due to poor time management on my part.)