I have an Emonda SL so it's not as light as the SLR model, stripped of it's Shimano 105 group that it came with and replaced with a Campy SR group, and I have it set up as my rain bike because I was able to fit full fenders on it. But I rode it around before mounting fenders for the winter and have to say, would not be slighted in the least if I had to ride it on any big trip versus my Colnagos. The Trek's "Ride Tuned" Technology actually does what they say. While not as compliant as the Domane with it's iso speed pivot, it does have a little give that I could notice over my Colnagos. But it wasn't so much give that it felt weird or mushy.
I looked carefully at both the Tarmac and the Cannondales, but the Trek ticked more boxes on all fronts for me and my intended use. First and foremost was fit and geometry. I ride a 61 Traditional Colnago, ideally, although I'll be building up a 59 Traditional shortly. The Trek 60 had almost identical geometry with a bit of front end differences in fork offset etc. My Colnago 61T has the same top tube length and seat tube anlge as the Trek, with a headtube that falls smack in the middle of Treks H2 and H1 geometry, but I got the H2 in the Emonda SL as that it all it came in, plus I thought the H1 would be too aggressive for me. Building this bike up was a treat... the cabling, the routing, everthing is well thought out. And I like the lines of the frame aesthetically. Not a single regret in getting this bike.
The closest Tarmac I would have gotten was in size 58. It would have worked, but the geometry on the Trek was closest to what I wanted. And as I wanted clearance for 25mm tires and full fenders, the Tarmac would not have fit the bill. I did not want disc brakes.
As for the Cannondale, while I work on several of my racing buddies bikes, the geometry just doesn't work for me. I'm really in between sizes both in headtube length and top tube length. So I ruled that out.
At the end of the day, I got the bike that fit me, first and foremost, as close as possible to what I know works for me, then looked at things like aesthetics, and clearances etc., and just an overall appeal. The Emonda checked all the boxes. And I didn't even look at the SLR version because of the direct mount brakes, not that I don't like them, but since I have my own unique mounting method for getting fenders/mudguards on high end road bikes, I needed the center mounting bolt on the brake for it to work out well.
So, if your previous Trek served you well for 17 years, that may be your best bet again. Unless of course, you just want a change for change sake. But I don't think you can really go wrong with any of your choices.