Jon,
Despite the complaints, all of us posting here are either using or considering AC. After all, why have user board section for requested features, and not expect the posting users to point out deficiencies, and expect a response from the staff?
For my own part, I can honestly say that AC has transformed my practice (positively) over the past 3 years, so that I produce a much more comprehensive and effective medical record, and essentially paperless. Wherever EMR is headed in the next few years, I feel I am ready, and with AC, I essentially did it myself, and not at the mercy of the vendors that you mention. Believe me I know the other side of the fence, since I was just soaked for a $7,000+ mandatory upgrade by my physician office lab vendor, Antek -- the second in 3 years.
However...some of the repeated requests (letter writer, imported items glitches, ERx, backup to NAS, etc.) are daily annoyances for some of us. Without diverting from the main effort, perhaps addressing a small number of these would be possible using a strategy of hiring or contracting with a "troubleshooting" programmer, with users who needed this function willing to pay extra for an "add-on", ie, formatting letters in Word, etc. This may be a naive suggestion on my part (I am one of those fools who donated money in advance to develop Opera, after all). I really have no idea what a project like this would cost, but by comparison X-Link has quoted me $4,000 for an interface between AC and my lab software. For 20 users, this would be a manageable cost, and if it helped the feature eventually be rolled into the next version, all users would benefit.
Anyway, I am one of your fans. But I reserve the right to whine...sometimes.