One rep told me that only mobile apps would run on Windows RT.
When I asked about the Surface with Windows RT, one rep explicitly corrected me, saying that "the Microsoft Surface RT has Windows 8 on it."
One rep told me "They're pretty much the same thing, there is no real huge difference beside the RT is more touch friendly." Minutes later, they admitted: "also it can not do an installation of x86/64 and desktop software."
When I asked what "x86/64 software" was, the rep told me this: "It's nothing you'd care about, that's more for people who are building their own software." "I honestly can't say there's much a difference at all when it comes to a regular computer user. For an average user the differences between the pro and RT are slim."
One rep correctly rattled off a list of features missing in Windows RT, including Windows Media Player, Windows Media Center, Remote Desktop, HomeGroup creation... but failed to mention anything about apps. When I asked "Those are the only differences?" they said yes, but went on to mention how the Surface wouldn't come with a full version of Office. I asked if I could install an older copy of Office from a USB-connected DVD drive. They said yes.
When I pointedly asked that rep if Windows RT had any software compatibility problems I should be aware of, they replied "The RT version doesn't have any compatibility issues as far as I can tell."
One rep said, unprompted, that I wouldn't be able to do any photo editing on Windows RT, adding that "all of that stuff you'd normally be able to do on a computer you can't do here."
Several representatives said the Surface ran "Windows 8 RT."
One rep tried to convince me that Windows RT was better than Windows 8 in every way, mentioning only pros (no cons) when discussing the two operating systems. First they insisted that the only difference between the Surface with Windows RT and the upcoming Surface with Windows 8 Pro was merely a different operating system, and then a different type of processor, and then that it merely had access to an app store (as opposed to being restricted to that app store) and only finally, after half an hour of probing, that I wouldn't be able to install my legacy apps on Windows RT.
One rep said that I wouldn't be able to download apps onto the Surface, period, "because it's a tablet." They added that the Surface Pro would allow downloads. I had to probe further before they clarified that the Surface with Windows RT could also download apps, so long as you did so from the included app store.
One representative said the Surface couldn't run Windows 8 because it "wouldn't be able to handle as much information as Windows 8 requires."
Two reps told me that I'd be able to install my Steam games on the Surface with Windows RT. One qualified that it would only work so long as I transfered them over USB.