note the two new fixes are in 0.2.2.7-alpha too

ChangeLog

@@ -18,6 +18,13 @@ Changes in version 0.2.1.23 - 2010-0?-??
 
 Changes in version 0.2.2.7-alpha - 2010-01-19
   o Major features (performance):
+    - We were selecting our guards uniformly at random, and then weighting
+      which of our guards we'd use uniformly at random. This imbalance
+      meant that Tor clients were severely limited on throughput (and
+      probably latency too) by the first hop in their circuit. Now we
+      select guards weighted by currently advertised bandwidth. We also
+      automatically discard guards picked using the old algorithm. Fixes
+      bug 1217; bugfix on 0.2.1.3-alpha. Found by Mike Perry.
     - When choosing which cells to relay first, relays can now favor
       circuits that have been quiet recently, to provide lower latency
       for low-volume circuits. By default, relays enable or disable this
@@ -69,6 +76,11 @@ Changes in version 0.2.2.7-alpha - 2010-01-19
     - New options for SafeLogging to allow scrubbing only log messages
       generated while acting as a relay.
     - Ship the bridges spec file in the tarball too.
+    - Avoid a mad rush at the beginning of each month when each client
+      rotates half of its guards. Instead we spread the rotation out
+      throughout the month, but we still avoid leaving a precise timestamp
+      in the state file about when we first picked the guard. Improves
+      over the behavior introduced in 0.1.2.17.
 
   o Minor bugfixes (compiling):
     - Fix compilation on OS X 10.3, which has a stub mlockall() but