I, too, was unable to attend the Olympia debates due to other commitments. However, I've done the Olympia thing several times before, testified down at Seattle City Hall, and generally am not really new to the whole process.
With that said, I'm going to suggest that neither party is exclusively right or wrong. Defying the stereotype is one tool in the box, and it's a darned useful one. To the extent you can get the members of the body you are lobbying and/or the press to identify with you (the old "hey, I don't agree, but that guy looks like my buddy bill", etc. bit), you've made a major inroad in influencing the course of legislation and winning over the public to your view - and the costume of the day *can* play a major part of that effort.
That said, there is *also* a place for sartorial choices of a less formal nature. The last thing our community needs is to be identified as a solely a bunch of "rich suits", particularly in front of a bunch of theoretically egalitarian Democrats (that coincidentally hold both houses of the legislature, and the Governorship). It doesn't do us any more good to be easily fit a stereotype by appearing as an all-white, all-straight, or all-male community - not only are these facades patently untrue, but they serve to diminish our influence. In this sense, if you're breathing, sober, and recently bathed, your presence is of benefit at such events.
More briefly - if you can't bear up under suit'n'tie, don't be shy, come ahead. Headcount, counts.
Now, with all that said, it *IS* possible to be self-destructive - both to ones self and to the 2A community. Passion is good, frothing is not. To the extent one can supply passion AND logic and fact in a relatively calm tone, one is doing well. The flaming line in the sand is crossed when ones comments are limited to "Yer violatin' my gun rights! YEARGH!! And Yer Twirling Bastards wantin' to destroy the country!! YEEEARRGH!!" they are not only not terribly effective in driving home a point, but they actively undermine your testimony and that of all others testifying in the same direction, by splattering "crazy" all over it. Not good.
Sartorial choices are helpful, but attitude is the killer app. If you are so passionate that you're reduced to "pirate-speak" (and it's not "Talk Like A Pirate" Day), or even anywhere NEAR that place on the spectrum...your presence is desirable and good...but others are likely better choices to testify, if *winning* is the goal of the day.
Now, to Open Carry. My position has evolved a bit, and is likely to continue doing so. That it unsettles Ralph Fascitelli, who is in desperate need of distraction until such time as he gets a life, pleases me. Beyond that, if it opens a few minds when a courteous sort in OC-mode politely and calmly interfaces with the press and politicians (and even random passerby) demonstrating their sanity and general non-scariness - why that's an actual win, as opposed to the guilty pleasure of discomfiting nanny-statists.