Hi Bucc
I am changing my view on the amount of marbling in a tri tip.
About a month ago I posted a thread (
http://www.bbq-brethren.com/forum/showthread.php?t=161809)
I put six Waghu tri tips (9.5kg - 21lbs in total) on sous vide at 55C (131F) and will pulled out after 10 hours. I iced them down, put five in freezer and took one for Sunday's lunch. The Waghu was 9+ marbling and was on grain for 600 days.
I have subsequently eaten/served four of the tri tips after heavy searing. There is no question they are tender & have great flavour and texture HOWEVER the fat has got to me. I now find I cannot eat other than a small potion. This is not like me - I generally love the fatty bits be it on beef, lamb or pork. In conclusion I will not seek (or pay the premium price) for 9+ marbling. What I will buy is meat with good quantity of visible marbling (say3) and that is available in both grass fed and grain fed beef.