In order to continue this offshoot I'll make things brief rather than distract from the "Hey check out my espresso machine".
First, I'm probably the best barista on my street but there's no assurances there, beyond that I have no idea. Second, the two points I was trying make were 1) The machine is important but not the solution, 2) There is a very big difference between a stock Office Lever and stock Brewtus II.
And now to the post you just made, MP...
I've always believed and will always support that espresso is as good or bad as the espresso drinker thinks it is. Espresso doesn't exist as a taste other than what the experience is for the individual in that particular moment. My palate, your palate and JohnF's are different. What I like, you might not. My sense of what espresso can be may be a much broader and wilder interpretation of what is "normal" than yours - that doesn't make it right or wrong, just different. Of course there are generally recognized tastes and smells, colors and textures and within that it's fair to say that horrendously sour espresso is, well, horrendous.
A lot of what goes in to a good espresso is simply a matter of removing or controlling variables and also understanding how those variables play against/with each other. Taking the Office Lever vs. the BII is a classic example of additional variables to manage, the Office Lever requires temp surfing plain and simple. No matter what routine a person has with a temp surfing machine, they can never precisely control/experiment from shot to shot to see what the variable called temperature may be adding/subtracting regarding the coffee. Sure, it's easier to be more precise with an Office Lever if mods are made, but, then it wouldn't be a stock Office Lever.
I'm not suggesting your espresso machine, or anyone else's espresso machine for that matter, is deficient in any way. My main thrust is... the espresso machine is important and can make a difference within the much larger puzzle of all the things I mentioned in my previous post. Ultimately, you currently have a machine that is producing the best espresso available and you couldn't be happier and that's what's important.
One of your questions,
"On the other hand you mentioned that you've had espresso on a $15,000 machine that was bad and an espresso on a $1,500 machine that was sublime. I'm wondering about the variables on that ... ie was the barista the same, was it the same coffee, was the water the same, was the roaster, grinder, storage, cleanliness and espresso-fu the same?"
really illustrates the point I'm trying to make. Even when the barista is the same, on the same machine, using the same water, grinder, bean, yadda, yadda, yadda, when everything was the same shot to shot - sometimes one shot is better than the other - huh? What could cause that? Was the technique realllllllly exactly the same, was that distribution just as focused, did the PF "clank" against the grouphead when it got placed in, was it a 1/2 gram off or could it have been a creeping differential pressurization in the boiler, ohhhhhh drat, it was the hot grinder throwing things off a bit due to the previous back to back shot-grindings which changed the subtleties of the shot. One potential variable amongst many subtle variables amongst many obvious variables, all playing off against each other in millions of potential chains. Espresso is as simple or complicated as a person wants to make it, a deeper understanding and a broader exposure to all things espresso has confirmed my "reverse pyramid" theory (it's my theory, mine, mine, mine, hahaha) which generally proposes that the more you understand, the more you understand how much more there is to understand. Love that one.
And so, for final clarity I will repeat... it's not the machine, nor the retail value of the machine that makes for good espresso.
I'm now intellectually espresso-fu'd out for the day. Time to go roast.