I'll give you a pic, but don't go telling me to paint the fence please...
First the old bike. I have been riding a Trek Equinoix 9.9 for about 5 years. Very happy with the bike, and once wrecked it and Trek backed it up with a solid crash program that allowed me to buy a new frame at a really good price. I am loyal, for they have been good to me. And they build a great bike.
I rode a size small TTX, (I am 5' 8", 32 inseam), but my shop ordered a medium a couple of months ago after going over the numbers with Trek. I am a pretty good AG'er, but won't be going to Kona anytime soon. My style is hanging on the nose, get comfortable, and ride hard. When I started reading the threads here on small vs medium for people my size, I unloaded a few "I think we made mistake" comments on my bike shop to maybe clear the way for a reorder if I was not completely happy. They were very confident, and they have been very good to me as well. So I stopped reading here, because it was not helping. I just wanted to trust LBS and of course Trek.
When I saw the bike assembled, I thought the top tube was longer than I would like, but it must be an optical illusion, because I understand it is very minimal from a small. But I swear it looked like a 56 frame. My bike has a 110 stem, and an SMP Glider shoved as far forward as it can go. I dropped the pads down to 1 full spacer in between the cradle and base. The key to my fit was I had maxed the seatpost, and wanted to get a little higher because the SMP seat lowers me when I am moving and grooving off the nose. My LBS swapped out the med seat post for a large, and that put max line back inside where it belonged. I test rode and smiled. This is a very fast bike. Much stiffer than the old TTX. More P like for sure. And this 5' 8" and a smidge frame fits perfectly for me at age 52.
I still have some things to do. I'm not sure on hydration yet. I have a PT on my training and race wheels, so I am anxious to see how the Garmen 705 performs. It looks cool, and will probably remount on an aero speed bottle. Accessories are expensive and make this bike, already costly, extremely out of reach. In many ways unjustifiable. But I have always owned the best Trek has made. I passed on the SSL, and waited two years for the SC. I think I made the right move.
On the trainer, I'm back on the SMP a little. Out on the road, I have a comfortable 90 degree arm rest for the first time in my life. It should make you medium dudes happy to know that this bike feels great for me. Forget all those numbers. Carl knows his stuff. A good LBS fit, and you will be in business. For me, Brielle Cyclery totally rocks the Trek SC world here in NJ.
I'll follow up here after Augusta 70.3. And maybe while there find another SC owner to compare notes and experiences. Good luck to all those waiting patiently for the SC.
"The trick, William Potter, is not minding that it hurts." T.E. Lawrence