I wouldn't go as far to say whiteboard interviews == bad company. I will evaluate the company if a whiteboard interview is run poorly however and consider it a bullet dodged.
going through / having just gone through this process this is where i've basically ended up as well... crappy interview experiences are universal enough that they don't disqualify a company automatically (though obviously i'm not terribly fond of them :-).
the one thing i'd add is that i do take particularly thoughtful / empathetic interview processes, interviewers who actually know and understand the question (rarer than you'd think), etc. as a fairly strong signal, as those sorts of things don't just happen by chance-- they are the byproduct of a culture of thoughtfulness (and thoughtful people tend to be thoughtful about most things).
I caught an interviewer red handed once by handing him the marker and asking him to show me. He tried and failed and then his coworker tried to fix his mistake and failed.
the one thing i'd add is that i do take particularly thoughtful / empathetic interview processes, interviewers who actually know and understand the question (rarer than you'd think), etc. as a fairly strong signal, as those sorts of things don't just happen by chance-- they are the byproduct of a culture of thoughtfulness (and thoughtful people tend to be thoughtful about most things).