Here is how I break it down:
Not sure what p411 looks like on the client side, but on my side the clients okays the providers - show up as a blurb: contact info, short bio, personality and acronyms; ie nickname, site (sometimes) phone (sometimes) & email.
Client is MUCH skimpier - esp if they haven't added any text. It has your name number and email.
Basically the same info I ask for in my "invasive" screening:
http://bluesbabee.com/contact.phtml
For me p411 gives a client 2 advantages: All the info I need to screen (link above) is there - you don't have to type it again.
It does lend credibility to both client and their refs.
On my end everything I need to check your refs is just a click away, thats handy.
The down side for me is there is No nothing.
A p411 okay is just that its an okay. If you are a GREAT guy, great client, nice guy...you get an okay. If you are an asshole who leaves skidmarks on the bed shows late stays over tries to bargain blah blah blah ....you get the same okay.
You're okay.
A reference is a totally different animal.
I sent a ref to Dallas a week or two back. Seen the guy 2 maybe 3 times but not in like a year or so? I didnt remember his name, sorta remembered his handle, wasn't real sure but ....I remembered what he looked like and what he had told me about himself and a few other details. "If that's him, he's a great guy." It was him and he got better than an "okay" from my reference (I hope because I sure meant it that way)
A reference should give me some idea of who YOU are. If you're ok with "okay" well ok. If a provider is ok with "okay"..well ok. If a provider isn't...well okay.
Okay?