My cynical side always raises a flag with this type of stuff.
Present a highly technical "evaluation" to "prove" (with bar charts and graphs) that your equipment is not quite correct for you. Oh, and by the way we will sell you the correct frame, stem, and componentry that is a proper fit...
From your detailed description, I don't get the impression this is the case. And they assisted in minor adjustments that didn't break the bank. So far, I'm impressed and will pursue this.