I have now had an opportunity to ride my CAAD 9 with the Exogram cranks. No issues with the slightly wider Q-factor so now I have a conundrum.
Do I go Exogram on the Evo Ultimate and replace the Hollowgrams? Eventually (probably over the winter) I want to get a powermeter and would like to be able to swap between bikes as necesary.
Therefore I would like to have the same crankset on both bikes.

My Hollowgrams in 172.5 50/34 with Praxis clover rings weigh in at 543g

The Exogram in 172.5 50/34 with stock rings weigh in at 523g

So if I went with Exogram with the Praxis rings I would be down to 492g.

Obviously there is a huge price difference and I could almost pay for two sets of Exogram for the price of one Hollowgram set.

I would say that it's not worth it. Exogram is cheaper, (probably) stiffer, and lighter (even with stock rings, which btw looks AWESOME ).

What about the new hollogram sl2? Is it worth upgrading to this or using praxis rings on the old red black chain set on the Evo?