The $179 BLU Win HD LTE brings a rare feature to the U.S. Windows phone market: It has two SIM card slots. That makes it ideal for travelers who want to carry business and personal numbers with them, or maintain their U.S. number while they also use a local SIM card overseas.

Of course, that's also true of the Win HD LTE's predecessor, the . The key feature the newer phone adds is right in its name: The Win HD was 3G-only, while the Win HD LTE adds three LTE bands for basic 4G connectivity on the AT&T and T-Mobile networks. For more advanced LTE support, you'll need to step up to a more expensive device, like the .

The Win HD LTE also bumps up the processor speed from a 1.2GHz Qualcomm Snapdragon 200 to a 1.2GHz Qualcomm Snapdragon 410. This is a respectable midrange processor, so performance will be even better than we saw on the Win HD, which was already pretty good in everything except action games.

This colorful phone's specs are otherwise quite similar to the competing Microsoft Lumia 640. The phone has a 5-inch, 1,280-by-720 IPS LCD. It has an 8-megapixel main camera, a 2-megapixel front camera, and 8GB of internal storage plus a microSD card slot. It supports 802.11b/g/n Wi-Fi and Bluetooth 4.0. 

The Win HD LTE is also one of very few Windows Phone choices available for the AT&T and T-Mobile networks right now. As of this writing, T-Mobile doesn't sell any Windows Phones at all. AT&T only sells the large, 5.7-inch Lumia 640XL. If you go directly through Microsoft, you can find the Lumia 635, 640, 830, and our favorite Windows Phone, the costly , all for AT&T.

All of the Lumias currently look like they're at fire-sale prices, hopefully awaiting a complete refresh of the line after Microsoft's announcement of Windows Mobile 10 devices on October 6. That makes the AT&T-locked Lumia 640 only $79 at the Microsoft Store.

Still, there are still some reasons you might want to consider Win HD LTE, even for $100 more. Most specifically, its combination of dual-SIM and LTE makes it good for travelers who frequently flit across borders, especially between the U.S. and Canada.

We'll have a full review of the BLU Win HD LTE soon. That said, we recommend holding off on buying any Windows phone until we know more about the Windows Mobile 10 lineup coming from Microsoft in October.