The game seems to be updated fairly frequently on Steam, with new parts, new peripherals, bugfixes, etc.

I'd love to buy the game on GOG, but am a bit concerned, since we often get updates late here compared to Steam, and sometimes don't get updates at all.

So... I guess I'm just hoping that a developer can confirm that they will continue to support the GOG version, and will update it in a timely fashion? :-)

AgentBirdnest If I were you I'd get it on steam. You can get it on humble bundle right now for 14 usd (It gets you a steam key) to save the hassle. The updates come to us whenever the devs are ready to release. I don't know about GOG though so I say just go for the steam version, and save yourself some frustration.
Edit: I forgot it is on sale for only 1 day and 4 hours while writing. I hope you see this soon enough.
Cheers, TML55

*Modded, due to advertising.

Thanks for the heads-up. Saw your link just in time, with 22 minutes to spare. :-P