diverdescent,
The sizing recommendations from Larry and Scott are based on years of experience fitting divers, and are as close to correct as anyone could give you. From everything you've said, ("My waist at the "widest" point is 40-44 inches, give or take, and I'm 5'7"), I would agree with their advice. (You never told us your weight.)
The important thing is for you to get the best fit, and the dealer will soon have you in front of them with a Lg and an XL BC to try on so you both will have an advantage.
One of the things I do as a rep for Zeagle is to teach dealers how to fit customers. (I've been fitting divers in Zeagles for almost 25 years.)
So here are a few of the most important tips: Look at this link for the current photo of the LTD.
http://www.zeagle.com/index.php?submenu=HeavyDutyBC&src=gendocs&link=RangerLTD
1. The vest is what you want to size first, not the waist band, so look at ends of the vest pannels where the waist strap is sewn on. This is the lowest part of the vest in the picture, in the front. Ideal fit is when the end of the vest pannel is directly in line with the shoulder strap, running vertically right across the tit. If it's too far forward the waist buckle will bottom out with no adjustment left on the strap, not good when you're wearing no suit at all. If it's too far back under the arm, the weight pocket will not be on your hip, but rather too far onto your back, especially when in a thick suit.
2. Always stretch the waist bands out before wrapping them so they will contract with suit compression. The waist bands would be best if set in the smallest or middle setting normally with no suit on. Look at the 3 plastic bolts that attach the waist pannels to the vest. The back 2 dictate the setting, and should be moved to the center grommit holes for you, no doubt because of your dieting possibilities. The third setting is not usually where you want them, unless you're just renting or borrowing the BC. You want to be in the middle of the settings with the most popular suits you wear the most often.
3. Start with the shoulder straps opened up enough to easily get into the BC. Attach the chest clip and center it so the shoulder straps follow that vertical line I mentioned earlier. Tall divers may want them in the lowest setting and shorter divers will leave them in the top setting. Pull the shoulder straps down but also follow the strap back under the arm slightly, not straight down. Make sure the waist band stays in place, not getting hiking up at all. The extremes are if the shoulder strap bottoms out on the buckle and is still loose, you need a smaller shoulder. If it's all the way out and it doesn't reach while standing up straight, obviously you need a longer shoulder section. Best fit occurrs when the curve of the shoulder panel is most comfortably matching the curve of your shoulder and arm.
There is a lot of lattitude and overlap in our sizing, which is good. I like my BC with very little extra straps dangling, but I live in Florida and wear a 7/5 jump suit as my winter suit for only three months. It might be good to bring your thickest suit and try it next if you have any doubt. Your suit is going to be a much bigger problem than your BC if you lose or gain weight.
The BC sizing for suit choices is not too tough to factor, but the possibilty of changing sizes due to dieting really throws in a curve ball.
I hope these tips help!
Chad Carney
FL Zeagle Sales Rep.
www.zeagle.com
www.mobilescuba.com
727-423-7775