I had to reread this thread before answering. At first I thought the OP was referring to ANY Windows 8 tablet. A second read reveals the question is about Windows RT, which runs on ARM devices only.
The main allure of Windows RT, IMHO, is the ARM processor and the long battery life. I am typing this on my iPad during my lunch break. Yes and own and use an iPad a LOT! But I am a refugee. That is I am a died in the wool Windows man, stuck using an Apple device, because of its reliability, long battery, etc. But I DON'T like Apple!
I don't just use the iPad for consumption. I use it to remote into servers and desktops at work, wo/ the pain of booting up a full blown PC first. I use it in meetings to take notes. My handwriting is pathetic, lol, so I have to type to take notes. But at the end of the day, while I like my iPad, it is STILL an Apple device.
My other tablet, these days, is a Samsung Series 7 Slate. While it is a true touch device, it feels like a fast laptop, that happens to be a tablet. The battery life isn't even half the iPad.
I have my eyes set on one the new Windows 8 tablets with the new Intel Clover Trail chips. The battery life is up there with the iPad, but it still is an Intel and runs most of my desktop software. I've read a review about an acer Iconia W510, which touts an optional dock keyboard reminiscent of the Asus Transformer line of Android tablet. I am taking a wait and see approach before buying a Clover Trail device.
While I am a definite Windows 8 fan, I am not so much a fan of the Surface. I have well defined needs that Windows RT doesn't address.