Now, the new $1,399 Samsung Ativ Book 9 Spin and $1,599 Ativ Book 9 Pro are challenging Apple’s computers once again.

The Ativ Book 9 Pro is a 15-inch MacBook Pro competitor with a powerful processor, discrete Nvidia GeForce graphics and a gorgeous 15.6-inch, 3,840×2,160-pixel-resolution 4K touchscreen display, while the Book 9 Spin is sort of like a high-resolution touchscreen MacBook Air with a 360-degree hinge that lets the computer double as a tablet.

Both are shipping this November in the United States.

There are plenty of new Windows 10 computers these days with 4K screens, backflipping screens and all manner of processors inside. What makes these Samsung computers stand out?

I just got my hands on the new Book 9 Spin and Book 9 Pro for a few hours, and they felt pretty great. Unlike most ultrathin laptops, which use a mix of metal and plastic components, or have frames that bend and creak, both of these PCs have rigid aluminum unibody frames that feel like they could withstand a rough ride in a backpack.

Just like the MacBooks they hope to supplant, these computers are machined from a single block of aluminum — only they’re a nice sleek black with beveled, polished chrome edges, instead of Apple’s traditional muted silver. The hinges feel strong, the keyboards feel pretty responsive (but thin), and the touchpads feel amazing for a Windows laptop both in terms of their slick surfaces and how quickly they respond to gestures. From what I can tell, Samsung picked some pretty great high-res touchscreens for these PCs, too.

Where many thin laptops skimp on connectivity (including previous Samsung computers), both of these computers have a host of full-size ports. Both the Spin and the Pro have three full-size USB 3.0 jacks and a full-size HDMI socket, while the Pro has a full-size SD slot and a USB Type-C jack that supports USB 3.1 data and DisplayPort 1.2 video output as well.