I liked the price of the X...but I was not a fan of the fabric. I know most people don't have any problem with it, but compared to the Revelation...well, there is no comparison. I ended up selling the X and keeping the Revelation.
Of course, I am a woman of a certain age and we tend to be a bit, um, sweaty at night. So I might be a bit more sensitive than others, but I did find the 30d quite plasticky.
If you can afford it, by all means go with the Revelation and don't look back.