FYI, I opted for the Checkpoint. There's several other things that went into the choice beyond just whether it would work well as a road endurance bike, with proper wheels. In the end I have a Checkpoint SL 5 on order. I should have it no later than the end of March. My plan is to add significant mods to it. The first one being a carbon wheelset. I actually want GRX Di2, but in the Checkpoints this is only available on the SLR 7 which has the more expensive version of the carbon frame. I don't need that. So, choice was to go with the SL 5 and upgrade, or buy more bike than I wanted with the SLR 7. The deciding factor was that I can get the SL 5 within 2-3 months and the SLR 7 was over 1 year!