The Mobile World Congress in Barcelona always has a bit of carnival barker’s edge, as everyone from giant phonemakers to the most obscure startups vie for the attention of some 100,000 attendees. This year, in addition to the usual packed hands on areas for playing with the latest devices from Samsung, Sony, and others there are a couple of autonomous air taxis you can sit in for a “ride” in virtual reality, a Batman versus Scarecrow VR game, and some kind of Google scavenger hunt that was little too convoluted for this busy conference goer.

But it’s a couple of the items that you can’t touch that are drawing the biggest crowds. Samsung, Huawei and TCL have all announced one form or another of phones that unfold into larger-screened tablets. And they’re all here on site–locked up in sealed glass cases. Samsung’s Galaxy Fold, which has a phone screen on the outside and opens like a book with a separate 7.3-inch screen on the inside, is set in a mini funhouse hall of mirrors display case that makes it hard to see the sides. That may be because the device is on the thicker and heavier side compared to the thin phones we’ve grown used to carrying.

When I sat down with Justin Denison, Samsung’s senior VP of mobile products, he was almost giddy in discussing the Fold, though he didn’t bring one along for closer inspection. Starting at almost $2,000, I’m not sure I’m as excited as Denison about the Fold’s signature feature of placing three mobile apps on screen at once. And even he concedes it’s a bit of a work in progress.

“I definitely think this device is for an early adopter,” he says. “Typically your early adopters are the ones that engage first, that find the most value in that type of innovation.”

TCL said it was holding off a year before announcing actual folding products, hoping to get under the $1,000 price level. As you’d expect, Denison hinted Samsung’s products would do the same. “With any technology innovation that takes (hold), you will tend to expect it to move down the portfolio but we’re not making any particular announcements or promises at this time,” he says. There will be a lot more to say when review units get into reporter’s hands ahead of the expected April 26 launch date.

Some people have been more excited about Huawei’s seemingly thinner Mate X device, which will start at $2,600. Here, the folding screen is on the outside. When the device is closed in phone mode, about half of the 8-inch display can be used on the front and half on the back. You unfold it outwards to get the tablet mode. It’s also locked up on display here although easier to see in an all-clear glass case. A friendly Huawei staffer even snapped a picture of the back hinge side for me. The shipping date of the middle of the year is a little vague, however, and Huawei phones don’t have wide distribution in the United States.

There’s obviously great utility in having a device that’s as small and light weight as a phone but offering a much larger screen when you want it. On the other hand, early versions will have trade-offs, like the higher prices, heftier sizes and likely software oddities. I think I’ll wait for the second generation. How about you?