sorry for the late reply.
I am currently using the 2008 US competition blend.
In regards to the taste vs visual issue, I think the issue stems from the mediocre world of american chain espresso that i have lived on (no, not starbucks, i work above a coffee bean).
I am a daily espresso drinker, but have only recently ventured into the home barista world. I guess the real issue is that to really know good espresso by taste is a matter of a LOT of experience. I have probably had 3 good shots of espresso in my life. The most recent was at 9th St. Espresso in New York. Before that, Intelligentsia.
I spoke to the baristas as much as possible about their techniques, but most of their insight were things i had already learned by reading articles here

That being said, I have a hard time identifying bitter/sour/sweet issues in my espresso. I guess I have been tasting these shots with only vague recollections of the killer cups i've had, and what espresso SHOULD taste like....
the reason visual aids help in a place like online forums is that i don't have the experience to actually share the "taste" accurately with you....and my camera isn't half bad.
I hope that in my experience with more and more coffee, I will gain a more refined palate, and can hone in my espresso making skills through describing the issues.
I will try to add taste descriptions with my subsequent video, but hope I don't mislead with a poor description.....but most importantly, thank you to everyone!