Here is how we track our progress for the performance improvements over at Paycento

MerchantSpeed.cs

        // TJS  2012/05/31 11:05   14 tx/sec
        [TestMethod]
        public void CreateSessionKeySpeed()
        {
            // restores a new private MSSQL db from backup and injects it into the self-hosted WCF backend API
            using (var ApiCtx = new PaycentoAPIContext())
            {
                // we have access to the db instance as well
                ApiCtx.RunOnDb(dbconn => {
                    var cmd = dbconn.CreateCommand();
                    cmd.CommandText = "Update foo set bar=1 where zomg=12";
                    cmd.ExecuteNonQuery();
                });

                var conn = new Paycento.MerchantConnector.PaycentoConnect("localhost", false, "application/xml");

                // invoke once to fire up service
                conn.CreateSessionKey(ConsumerKey, ConsumerSecret);

                var p = new Profiler(MinTxPerSecond: 100, TxTimeOutInMs: 3000, a: () => conn.CreateSessionKey(ConsumerKey, ConsumerSecret));

                p.TimedOutJobs.ShouldBe(0);
                p.InvokesPerSec.ShouldBeGreaterThan(14);
                p.AverageMsPerTx.ShouldBeLessThan(1500);
            }
        }