With such a winning design idea, you’d think nailing the particulars would be easy. But as they say, the devil is in the details, and my satisfaction with the Stack was short-lived.
The Stack system consists of four modules, identical in their measurements at three inches wide and just under six inches long. Thickness varies from about a half inch to a full inch, depending on function. Said functions are storing data (a 1TB hard drive), providing a personal Wi-Fi network (an 802.11ac router), powering the stack and charging your devices (a battery), and making noise (a Bluetooth speaker).
The modules are priced at $220 for the router and hard drive combo, which acts as an ad hoc NAS box; $70 for the battery; and $100 for the Bluetooth speaker. Though the hard drive and router are sold as a package, they may also be used separately, as may the battery and speaker.
Once the Stack was configured and updated, everything worked. But I experienced several minor issues, starting with the setup. I know wireless is the go-to for most people, but there’s an Ethernet port on the router, so why can’t it be used it to configure the unit It’s not that hard to dual-purpose (Internet and local) an Ethernet port.
Instead I had to go grab my iPad, then when the iOS app failed because a required button wasn’t visible, I was forced to boot a Windows laptop to initialize the router. This involves connecting to the router’s hotspot, downloading and installing the Stack Assistant, creating passwords, then setting the whole thing to operate. If you operate from a laptop as a matter of course, you can pretty much ignore that gripe.
I also have some quibbles with the design. Each module has a mating port on the top and bottom consisting of 14 exposed metal (magnetic) contacts. Fine. Except that the topmost port remains exposed. It's kind of ugly, and when I laid some DVDs on top of it, the red light on top of the uppermost module started to blink. That's Stack-speak for "I'm trying to join the stack now." How about a cap to cover the uppermost port Quibbling Perhaps. Perhaps not.
I was also not particularly fond of the 10/100 Ethernet port's position on the back side of router, when there's room 90 degrees away on the end—where every other port on all four modules is located. If you’re making design a reason to buy, little things like cable clutter matter.
All those were mere annoyances, but there was one particularly vexing operational issue with the Stack—unless you completely isolate the battery, it drains very quickly. I'm not sure what kind of maintenance is required by the other modules, or if this is a bug, but I soon learned to keep the battery separate from the stack when it wasn't in use, in which case there was no significant drain over the span of a week. A bit of a pain that.
Speaking of power, all four of the units may be powered and/or recharged individually via USB. The hard drive has a Standard-A USB 3.0 connector, while the other modules use micro-USB types.
The big disappointment of the Stack is the Bluetooth speaker. There’s nothing wrong with it operationally, it just doesn’t sound good. Muddy with a dirty midrange sums it up. For phone calls, it’ll do—barely. For music Forget it.
Note: The upper portion of the speaker enclosure acts like a coupled planar transducer that needs to be exposed at the top of the stack (forget the photos showing it in the middle). Otherwise it sounds even worse.
The speaker has its own battery so it can be used on its own. There’s also a headset jack, which you’ll probably want to employ given the lack of sonority. Lenovo claims eight hours of runtime for the unit, which is 2x2 watts (power of the amplifier). I’ll take its word for it. There’s no way I could listen to it for that long.
The performance of the Stack hard drive was a welcome return to quality. It managed about 125MBps reading and writing over USB 3.0, which is about what you’ll get from a good external drive from Seagate or WD.
You can use the drive as direct attached storage, but it’s also available as a network resource (and mapped automatically as a Windows drive) when you’re connected to the Stack router via Wi-Fi. The router runs on Linux, and you have to drill down a couple of layers to get to your files (DISKS/SDA1/…) but it’s actually formatted in NTFS.
The hard drive’s power state is controlled by the router so it doesn’t have its own power button. It also turns on automatically with USB, so that’s not an issue. In my first hands-on, the power light didn’t stay on, but that was fixed by a firmware upgrade.
I had no difficulty connecting to either the 2.4GHz or 5GHz bands of the Stack 802.11ac router. Range and throughput were both quite decent. The router may also serve as a bridge to another Wi-Fi network, though it still functions as an independent network—you can't inherit the parent's DHCP assignments or network resources.
3G and 4G dongles are supported via the router's USB port, but the documentation only mentions types used in China. Lenovo said just about any module should work. Dial-up is also mentioned in the documentation, but the app doesn't allude to USB modems. I can tell you that the Shark Leopard modem (yes, I know) that I keep around out of a sense of nostalgia didn't register on the router's radar. If 3G/4G/dial-up capabilities are important you, bug the company for more info. Maybe it'll be more conscientious about detailing such things in the future.
Nicely, especially in light of the poor speaker sound, there's a DLNA server on board. It's labeled miniDLNA, which I'm guessing is because it only streams music. But it does supports a nice variety of audio file types including MP3, WMA, M4A, and even OGG.
Weighing in at 8.8 ounces, the power-cell battery is worthy of the name, providing a whopping 10,000mAh of juice that will keep the stack operating for a decent amount of time. If, as I said before, you detach the battery when you're not using the stack.
As with other travel batteries, you can use it to charge your mobile devices. In this, case, two at a time via dual standard-sized USB Type-A ports.
I like the Stack as a concept, and once I’d endured the pain of setting it up and debugging it, I enjoyed using it. But for $390, I'd like to see more attention to detail, documentation for the U.S., and much better sound.