I didn't say what i would recommend lol...here's a list with pros and cons:
acer iconia w510: pros: best battery life and can extend it with keyboard dock for 9/16 hours. Great price: 599$ for 64 gb model and 150$ for dock
smallest and lightest tablet, about same weight and size as ipad
cons: a little plasticky, not necessarily cheap feeling but not built as well ad others. I haven't used the keyboard but on a 10.1" it will
be cramped, and I've heard it a little cheap feeling, also I've heard of touchpad issues although they say a driver update is
in the works
hp envy x2: pros: fantastic build quality, very thin and lightweight, little bigger screen 11.6" (could be a con for some), its pretty(only dockable
tablet that actually looks like a laptop and not a tablet docked into a keyboard dock), great touchpad, pretty responsive (like w510), optional active digitizer stylus
cons: I own it so there are no cons, jk
, keyboard is a little shallow, but its full-sized so its still pretty good, not as many ports, only 2 usb on dock and 1 full hdmi, tablet/dock sold only together for 850$ so a little pricey for an atom, same complaint with w510 although its 100$ less (may be a pro to some, like me unless you only want the tablet). Battery life is decent at 7 hours, it will last a full day, not as good as some others though like the w510 or arm tablets
acer iconia w700: pros: once again, fantastic build quality and screens, good amount of ports for a tablet, 1 usb 3 and i think micro hdmi, snappy performance (i3 model), great price, 700$ for i3 touchscreen tablet, don't know if there is an active digitizer for it
cons: as I said earlier, a little heavy for a tablet, battery about 6 hours, not bad for ivy bridge, but still a little low for a tablet. Crappy dock, it feels really cheap, is quite ugly, and a little complicated with 2 parts to assemble to make it work, Bluetooth keyboard feels a little cheap, so do most others to be fair, but you can by another if you want.
All in all, there aren't many true x86 windows tablets out yet. The thinkpad helix looks nice if you want to shell out 1500$ for it, although no one's used it yet so wait for the reviews.
No reviews out yet for the surface pro, but I think the battery isn't going to be very much, probably around 4-5 hours, and while I like the keyboard covers, I can't imagine the kickstand would sit on your lap very well, it looks like a table only tablet in its "laptop" mode
I guess it depends how much power you need, I went with the atom for the battery life and I would recommend the same unless you need to do a lot more than what that will offer you.
Also look at convertibles too, the Lenovo thinkpad twist and yoga 13" are nice. I haven't played with it yet but the Dell XPS 12 look like it could be a real winner. But beware with the convertibles that its still a laptop so even though they look and function like a tablet, they are still the same weight as a notebook, so they're not as portable as a tablet.