Well for starters, where are you located? It's possible that there's a GHer (or a group of them) that will offer you the opportunity to try some boards out. Some people like not leaving the home row to do most of their tasks in a 60% keyboard, but I've seen plenty of people buy a 60% for the looks and flip it after 15 minutes to a couple of days without really truly giving themselves a chance to adopt the new layout.
The new Das 4c tenkeyless uses Greetech switches, which as far as I know haven't really been reviewed/vouched for. Duckys are pretty solid, and the Corsair RGB line has been plagued with firmware problems since the beginning, as well as their controversial discontuining of the MX blue variant of those boards.
No one can really decide for you; as you've probably seen on the forum, everyone has widely varying tastes in keyboard layouts and switches

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