A:AnswerHello Mitch, yes this will work without the G-hub software. You just will not be able to customize the keys or RBG lighting without it.
-Danielle from Logitech
A:AnswerI bought this as a replacement for a keyboard that did accidental strokes. After a few months of using this at work every day, I haven't run into that issue, which I was very sensitive to. I can't say how long ten it will hold up, but it seems solid.
A:AnswerHello, the G815 was not designed to support O rings. If are looking to have quiet keys, we recommend either the Tactile or Linear switches that come with the G815. Thank you for your question, have a great day. -Ricky from Logitech
A:AnswerHi Glow, The G815 LIGHTSYNC RGB Gaming Keyboard does have an Echo Press effect that you can access via the G Hub software. There are thousands of profiles and lighting schemes that other gamers have created and shared. As far as the gradient glow effect that you mentioned, I couldn't find one on there. Hope that this helped and that all is going well. - Richard from Logitech