In my role as kink consultant, this topic ranks high on the request list.
First, “subspace” refers to more than one thing, but most people are asking about “flying”. Subspace is also the place subs go mentally when deep into the role. I’ll stick to the “flying” aspect here.
My personal reaction tends to be mild disorientation. Other people can give you a better idea of how it feels, especially when it’s more intense. From my observation and experience, I know that one extremely common reaction is losing track of time – hours seem like minutes.
“Why’d you stop? We’ve barely played!”
“Sweetheart, it’s been 90 minutes and my arm is tired.”
I’ve heard such conversations at parties. Similarly, my Dom, who likes being waxed, tried to accuse me of not spending enough time on him. I had the empty wax pots to prove my case.
For deeper subspace, these links will get you started. There are many others out there.
These are from a site I frequent for BDSM information:
I found this in a recent search and thought it was worth sharing:
This is from someone I know personally and trust. He’s written on a variety of kink topics; the links at the end of the interview take you to some.
New item (added 9/7/15) from a favorite blog, the Sugarbutch Chronicles http://www.sugarbutch.net/2015/08/sub-space/