I tried MM for a little while in BC, but beyond that I've been exclusively BM. My confidence comes from the fact that I've played with numerous marksman and survival hunters with differing levels of gear (usually better geared than myself), in a variety of different places (heroics, 10mans, 25mans) but I've always managed to out DPS them with BM. So in that sense, you could say I've tested my spec by simply comparing it directly with experienced MM and SV hunters, starting out automatically at a disadvantage with lower level gear. I would argue that taking that approach is likely to give you a far better idea of your actual comparative performance, at least for myself, as I would Spreadsheets are cool and all, but until a Blizzard created spreadsheet comes out their accuracy is always questionable because they simply can't replicate the same variables found in-game.

If you're really unsure, I'd recommend at the very least just spending the gold on a respec, try out the DPS, and see if it's even comparable to what you're pulling now. Gems and enchants are nice, but if you're already setup for MM you won't need to switch them over to BM in order to have a good idea how your DPS will change.

As for your raid leader, I'd recommend you simply don't show up with an exotic pet, and don't say anything about it. It's been my experience that simply calling attention to the fact that you're specced BM typically will be the only time others in your raid will say anything, which of course is based on their preconceived notion that BM is bad. Considering most hunters are specced BM until they hit 80, it's easy to see how personal experience playing with fresh newbie hunters specced BM can negatively affect someone's opinion on the spec. Obviously they'll probably catch on when they see your pet grow giant and red, but by then it'll be too late and they won't have any room to complain when you're still pulling solid DPS. In a nutshell, you don't have to go head first into the spec if you're unsure about it. Just try the respec to see if it suits you.

I could roll MM and survival, but given the fact that I've spent the vast majority of my time playing BM and testing out different specs to find what's worked best, it would hardly be fair for me to then "test" it against Surv/MM as you say because I would obviously still be biased toward my own spec (BM). I respectfully disagree with your view on it being "unfair" to test your DPS in a live, "real world" in-game setting. Spreadsheets can be useful tools at times but if they can't carry over directly to real gameplay results due to someone's computer (for a game that's been out for several years now) then what good are they? I appreciate the feedback though and hope to incorporate spreadsheets in further articles to solidify the points I've made.

As for the other two specs, I invite anyone who feels confident with their hunter build to write me and talk about contributing, as I hope to have numerous authors on this site at a certain point. I'm hoping to incorporate the concept of competition rather than comparison -- Have everyone build their very best for their spec and pit them up against each other, rather than having one person attempt to address all specs and potentially allow one to rise to the top due to biases or lack of experience with the others.