I think the primary focus for this facility has been raw speed.  

In my understanding the primary usage of positional is to be able to translate sentences more fluently into another human language.  This is normally not necessary for log statements, as you are fully in control of both message and arguments.  What would your use case be?

From: logback-user-bounces@qos.ch [mailto:logback-user-bounces@qos.ch] On Behalf Of Brett Walker
Sent: 8. februar 2013 00:51
To: logback users list
Subject: Re: [logback-user] commons-logging -> sl4j -> logback

It’s may bad. {} is the only syntax allowed

It would be a nice addition to have positional, but how warranted is it?

Brett

From: logback-user-bounces@qos.ch [mailto:logback-user-bounces@qos.ch] On Behalf Of David Harkness
Sent: Friday, 8 February 2013 10:46 AM
To: logback users list
Subject: Re: [logback-user] commons-logging -> sl4j -> logback

On Thu, Feb 7, 2013 at 3:35 PM, Brett Walker <brett.walker@geometryit.com> wrote:

This avoids calling the toString() method on the objects until the log message is actually required to be logged.

Sorry, Brett, I changed the subject without actually changing the subject since it was semi-related. :) I was asking about "{0}" versus "{}".

David