SOAP Proxy performance regression between 6.0.0 and 531GA

There is performance regression on soap proxy between 600 and 531GA -37.25%

Reproducers attached.

Steps to reproduce:
FSW6:
1) unzip sy-camel-soap-proxy.zip
2) build the reproducer:
$ mvn clean package
2) deploy the reproducer - copy the packaged jar into server's deployment directory
3) using HTTP client send a sy-camel-soap-proxy-request.xml request to following url:
http://${server.host}:${server.port}/performance-camel-soap-proxy/proxy/ReverseService

SOA531:
1) unzip http_gw_soapproxy.zip to quickstart directory
2) build and deploy reproducer
$ ant deploy
3) using HTTP client send 5kB_soap_reply.xml request to following url: http://${org.jboss.esb.server.address}:${org.jboss.esb.server.port}/HTTPGatewayProxySOAPProxy/http/PerformanceTest/HTTPGatewayProxySOAPProxy