The response is an awesome board, but this could really be said about any board i suppose.
I am 6 ft 165 lbs
I rode a 145 response once when i demoed a larger one for a larger friend and still had a great time on it. even at the largest size it still felt lighter than the last foam board i rode (2004 hyperlite byerly 137)
there are no rider weight specs listed for 2008 and 2009, but 2007 response 145 recommends for riders 185 and up
never ridden the 08 (or 09) murray, but i'd love to try it due to its unique rocker pattern (though i doubt it would sway me from flex in the end personally). there are some threads when the pay-it-forward murray boards were being passed around last year. try reading them for some opinions too. a wealth of comments there for ya from every size of board too
murray 135 http://www.wakeworld.com/MB/Discus/messages/65919/563738.html
murray 140 http://www.wakeworld.com/MB/Discus/messages/65919/562679.html
murray 145 http://www.wakeworld.com/MB/Discus/messages/65919/564734.html