Remarkable is direct-only I believe, but they do have a 30day return policy.

As for the software/sharing, they have desktop (Win, Mac, Linux), Android and iOS apps and their own cloud hosted service for syncing documents, inks, ebooks, etc amongst your devices and the tablet. The apps are a little clunky (due to cross platform widgets) but you can quickly export a PDF of a drawing or drag in an ebook (PDF/ePUB) and it'll auto sync to your device.

P.S. The device itself is quite hacker friendly, it supports SSH over USB out of the box and they've shared their cross-compliation toolchain.