The Howard Hill, The Tennessee Classic, The Cloverdale Nationals, The Traditional Bowhunters of Florida State Championship, the Alabama Society of Traditional Bowhunters State Championship, etc. etc. etc. aren't exactly sanctioned tournaments, but you will find some of the toughest competition in the world at them.
I wouldn't mind trying my hand at an IBO or ASA tournament, but I don't know of any in my area. I believe I'd prefer the more laid-back environment (obviously I don't know this from experience, just from talking to folks) of the shoots I attend anyway. Well I take that back--I did shoot in one sanctioned field archery tournament several years ago--I didn't go back, due to the fellow running it being a bit too stiff-necked, and it shut down after a year (probably due to the reason I didn't go back). I don't remember if I came in first, last, or somewhere in the middle--other than the aggravation, it was one of the least memorable shoots I've attended.
Most of the folks I know (myself included) go for fun--to shoot, see vendors, socialize, etc. etc. Bragging rights/dust collectors are ok, but the status is generally very short-lived with a few exceptions (some that come to my mind are Rod Jenkins, Ricky Welch, Bill Lesley) and they still have to pay for a cup of coffee at Hardee's (think Rod will qualify for the senior discount before too much longer though) :D
I've won a few state championships, won and placed at a few other big shoots, and I'd bet 99% of the people that were shooting with me don't even remember it--much less anyone else. Heck, I'd have to look at the trophy to remember when and where myself. Figure there's as many or more remember the big messes I've made at tournaments as the ones I did ok at.
Anyhow, just because a shoot isn't sanctioned doesn't mean you won't have stiff competition and a good time. I've seen a lot more competition at some smaller shoots than I've seen at some state shoots.
Chad