First off, congrats on the new frame! Nice job on the parts swap with no repair stand, the cat seemed happy to have you on the floor too!
i don’t know much about that Willier frame but handling is essentially all geometry related so good chance that your new steed’s geo matches closely with the old in terms of seat/head tube angles, wheelbase and fork rake/trail. Funnily, I can still remember when carbon was becoming “the thing” the original frames were all about road smoothness and absorption ideally without being too noodly. Then they started getting stiffer as construction methods evolved. The great thing about carbon is it’s so versatile in terms of how it can be used to effect various ride traits through layup and uses. Now of course all things come around and you have many (myself included) in the “steel is real” crowd who crow about the smoothness of the very same materials that killed our butts in the past (maybe we have more ass padding now).
still, I love carbon for how it absorbs road shock better. I’m sure that’s why you mention feeling less tired at the end of the ride. Tip for even more comfort, look to your wheel set and tire choices. You can probably make easy changes there and help with your comfort both on long rides but especially in curves and corners. It’s amazing the difference between a 23 and 25c tire with a psi change can make.
Enjoy the ride and stay safe!