Cannondale Topstone or Specialized Diverge E5 Elite?

If you can afford hydraulic

If you can afford hydraulic disks you should get them over mechanical every time. I have both and although the bike with mechanical disks is lighter and feels fantastic to ride my go-to bike is the one with hydraulic disks because it inspires so much confidence when descending quickly.

Few comments:
Few comments:

– Both Cannondale and Specialized are big manufacturers. Your money may go further with another brand.

– The difference between a 2×10 drive train and a 2×11 is small.

– Diverge models at this price range use mechanical disc brakes, which require a lot of messing around adjusting the pads and (for me) have pad alignment problems which cause the bite point to recede as the pads wear. The Topstone has Shimano hydraulics which should require much less maintenance.

– I ride a Diverge myself, but the E5 Comp with the Future Shock, which should be comparable in price and spec to the Cannondale you linked, if not less expensive now. If you intend to ride a lot on rough surfaces then I wouldn’t ride a Diverge without a FS – some will disagree but I notice a fair bit of difference compared to my other road bike, on which I’ve hurt my wrists a few times on potholes and unexpected bumps.

– I’ve had some issues with spokes on the Axis Elite wheels on my Diverge.

Of those two options, the Cannondale is the better bike, but given the price range then that is as expected.