Not much to add as I agree with every comment so far. Reviews are a lifeblood of UKP but no-one should feel compelled as long as their contributions are valued in some way. If you value a forum, it's good to give something back is my view. But protect your identity since you never know if you will wish you had in the future. I sometimes leave it a few days or longer to make it harder for a prossie to identify me from my review. I always try to be honest and never say anything I'm ashamed of, but it's for punters, not a media-circus of the occasional whacko who might read it. Prossies have mates who are prossies (often it's the only sort of 'mates' they have) which is why perfectly normal, decent, 'punter-supportive' prossies can turn and "stick together with their sisters" at a moment's notice. Not only prossies, but your boss at work might read it (how do you know he's not a 'reformed' punter?) or your wife or worse.
Reviews only have meaning in some sort of context, like knowing the reviewer is genuine and having an idea of their standards.
If a girl is hot and new, given the success of the forum, I maybe want to bang her a few more times before passing on the details publicly. (Though I'll maybe share by private PM to one or two regular members who I can see have similar standards as myself.) Too often after a few good reviews, a prossie puts her prices up and is harder to book. So I think, get your oats and then share them if you have time and inclination, and why shouldn't you?
If you have fucked, or intend to fuck, established female forum members, then bear in mind potential repercussions.
Fluffies can ignore most of this, but if you think giving a good review leaves you shining white in pro$$ie eyes, I disagree, whether it's fluffie or not! I gave a good review once to a hot little number in Edinburgh who went subsequently berserk. She had fantasies above her station and liked people to think she was some superstar to the elite mostly doing four-figure bookings. Prossies want business, and good reviews are business, nothing else (I had a friend once who flogged her fanny for a while and told me, "Do you know, I get genuinely wet at the thought of being paid!")
Reviews on here are for other punters. I try to put myself in someone else's shoes and imagine what the discerning punter would want to know before deciding to book someone. Do I have something to add? A list (without the soft-porn talk) of what services she gave me might be useful, together with a link, price I paid for how long, approximate location, and how I rate her looks and attitude. Just saying what she says she offers, a long paragraph on my knob, and lots of vague adjectives are probably not only less useful for punters but more appropriate to a wankfest or prossie site. If I say she was 'great' or 'good value for money' then it's more helpful if the reader can answer the question, "compared to what?" I know that's hard sometimes and reviews come easier to some people than others, but I keep mentioning these things in case it helps new reviewers.
You could even use the reporter's cliché, the five W's. Who? What? Where? When? Why? That can usually be condensed into one sentenece. Then list factual stuff someone else should want to know. I suppose the other advantage of waiting a day or two is that it is less likely to be one's cock talking.