If I go with the Trek Domane SL 6, I need to choose between the Shimano 105 Di2 and the SRAM Rival.
the LBS (Landis Cyclery, Scottsdale) had recommended the SRAM electronic shifting for my Ritchey Outback breakaway. I will need to do some research to see which way I will go. on the Trek website the SL 6 Gen 4 with SRAM is $600 more expensive. It it is that much better, I am good with that. One concern is the chainring size on SRAM appears to be smaller, 43/30 vs 50/34 for Shimano