How can a Paralane and a Suprersix both be perfect geometry. Isn't the Paralane more endurance like?
If you need a stack of spacers on the look in XXL than most likely you will be happier with endurance geometry. Some of these bikes do come up short but don't be afraid to size down and go with a long stem to get your fit. The nice thing about this approach is that if offsets some of sluggish handling that these bike often possess. For example, I think a Domane SLR would be nice but not in a size 62. At 183 cm/6 feet, I would ride a 56 with a 130 or 140 stem. (Although I think that super low bottom bracket might not be to my liking.)
Here's how the geometries of both the Paralane (XXL) and Supersix (63) can be perfect.
Paralane XXL Reach: 404 Stack: 630
Supersix 63 Reach: 411 Stack 626
Extremely close and I can go with a 120 stem on the Paralane vs a 110 on the Supersix. Stack is virtually identical. Thus, the "race" and "endurance" monikers don't mean much in terms of fit. I think the handling will be different in that the Paralane has a longer wheelbase and more slack head tube angle.
I see. However I have a philosophy that stems should be to scale - big bikes should be fitted with appropriately long stems. I appreciate we all need to do what we must to get our fit, but if you are putting a 110 stem on a 63 Super Six than I suggest it is not the ideal geometry for you. What happens if as you age you want to be a little more upright and the bars a bit closer? You haven't got a lot to play with. At your size IMO it is better to find stack that allows you to run no more that 20 mm of spacers and at least a 120 stem, 130 or 140 even better.
FWIW I went through the same process as you. I needed geometry that wasn't too aggressive I but wasn't willing to settle for an endurance bike. I still wanted racy and light. I ended up settling on a Parlee Altum - very light and very racy. You should check the geometry for reference. It comes in disc but the problem is that it will kill any reasonable budget.
I have an overall aversion to the various "endurance" and "all-road" models that are flooding the market. That is that they are battleship heavy. Even when spec'd with absolute top parts, they are not light. Part of it is that they mostly only come with discs which add a pound, and also the frames are heavy, rarely utilizing the lightest carbon layups.
When we ride disc brakes the whole deal of braking is just like a leaving a fart. It happens and then it's over. Nothing planned and nothing to get nervous for.