I turned on the full headers so that I could see the description of the rules 
that my messages were hitting, and what score each rule received.  I liked 
being able to quickly scan through the scores in the X-Spam-Report header to 
see what were the "big hitters" either positive or negative.  In SA 2.55, the 
scores were all nicely lined up.  Now that I'm using SA 2.60, the rule name has 
been added to the line prior to the score.  (I'm happy to see the rule name 
added to the description line, but...)  Since the rule names are not all of the 
same length, the scores are no longer lined up in the report format, and are 
buried amongst a lot of text.  It's become rather difficult to scan through the 
lines to see the individual scores.

I've included the X-Spam-Report headers from some sample ham that I had saved.  
I'll note that they're not the same message checked twice, they are two random 
messages I just picked them as an example of the formatting change.

Headers from a sample 2.55 message:
X-Spam-Checker-Version: SpamAssassin 2.55 (1.174.2.19-2003-05-19-exp)
X-Spam-Report:   ---- Start SpamAssassin results
  -6.70 points, 5 required;
  *  0.1 -- From: contains numbers mixed in with letters
  * -0.5 -- BODY: Contains what looks like an email attribution
  * -0.5 -- BODY: Yahoo! Groups message
  * -5.4 -- BODY: Bayesian classifier says spam probability is 1 to 10%
  [score: 0.0341]
  * -0.4 -- BODY: Contains what looks like a quoted email text
  ---- End of SpamAssassin results

Headers from a sample 2.60 message:
X-Spam-Checker-Version: SpamAssassin 2.60-cvs (1.193-2003-06-13-exp) on
    eclectic
X-Spam-Report: * REPLY_TO_ULINE_NUMS  2.0 (Reply-To: has an underline and
    numbers/letters)
        * FROM_HAS_MIXED_NUMS  0.8 (From: contains numbers mixed in with
    letters)
        * BAYES_00 -5.2 (BODY: Bayesian spam probability is 0 to 1%)
        [score: 0.0000]
        * MAILTO_TO_SPAM_ADDR  1.1 (URI: Includes a link to a likely
    spammer email)