I think it needs to be mentioned that one doesn't really 'need' to accomplish subspace to have a great experience when playing with a partner.
Sometimes people talk about 'subspace' as the end all, the goal to be achieved, making others question their success in having a great experience without it
I'm not! saying that is the case here, I'm just mentioning it to those that might be reading this and wondering what is 'wrong' with them that they've never experienced it...
For me the purpose to all the 'play' is to have great sex. I can have 'good' or 'just ok' sex anytime, by normal means and even have an orgasm - but in order to have GREAT sex it needs to be more.
One of the reasons is that my brain won't shut up, not even when I'm having a great time and concentration JUST on what is going on right then at that moment.
Dabbling with BDSM in many of its glorious facets helps my brain FOCUS on just one thing, my body and the feelings I'm having at the time and so MY personal Subspace success is not necessarily the euphoric feeling as described above, but a much more subdued victory over my brain, the quietness that comes with just feeling and not thinking.
When the nipple clamps bite just that bit too hard (not really) and my wrists chafe from being stretched tight overhead, I all of a sudden concentrate on my body and the here an now and everything outside falls away. I've achieved MY subspace...
Subspace can come in many different shapes and sizes and none of them are 'righter' or 'wronger' than the other!
Peace to all!