ProsAmazingly slim; incredibly fast
ConsHas a lot of extra features, but many simply do not work reliably; sleek design marred by unstable base and side-facing cable ports; does not work reliably with Windows 8.1
The Rosewill RNX-N600UBE Dual-Band Wireless N Adapter is a desktop wireless adapter using the USB 2.0 interface. At 3.5" x 2.2", it has approximately the footprint of a credit card, but is nearly 0.5" thick. Unlike many external USB 2.0 wireless adapters, this one is not designed to be mounted directly in a USB 2.0 port, as it's far too large. Instead, it's designed to sit on a desktop, attached via the included USB extension cord. It has four rubber feet that help keep it in place, as well as two large antennae that can be individually positioned to get the best reception (this really does matter, actually).
Like many 802.11n adapters, this one offers "300mbps" speed, in this case both uplink and downlink, leading to the "600" in the product's name. But that rating has much less to do with actual performance than the frequency band on which it operates. That, in turn, is the N600UBE's main feature - dual-band functionality (2.4GHz and 5Ghz). It's among the least expensive dual-band USB 2.0-based adapters currently available. Setup of the N600UBE is relatively strightforward, although Rosewill tends to ship its drivers on a mini-CD, which cannot be used in some DVD drives, including any desktop drives mounted vertically. Downloading the drivers from the Rosewill website ahead of time might be worthwhile. Windows can also download the correct driver for you if you plug in the adapter while connected to the Internet via an existing adapter.
The performance of the N600UBE really puts it in a rare class of USB 2.0 adapters, primarily based on its amazing throughput on the 5GHz band. While the specified speed is the same on both bands (300Mbps), anyone who has used wireless networking since the dawn of the technology knows that those ratings are completely theoretical and impossible to achieve in practice. The advantages of the 5GHz band, however, are far from theoretical. While the higher frequency may have a slightly shorter range, the less crowded nature of the 5GHz spectrum more than makes up for that fact. Whereas 2.4GHz-frequency adapters, regardless of whether they are rated at 150Mbps or 300MBps, typically top out at 32Mbps (4 MB/s), this adapter achieved a consistent 84Mbps (10.5 MB/s) in sustained transfers between networked computers. That's nearly three times as fast! Unfortunately, don't expect the N600UBE to work wonders on the 2.4GHz band - it achieved the same 32Mbps that every other adapter we tested provided.
Note that the throughput found above was achieved despite the 70% signal strength reported by the N600UBE adapter on the 5GHz band - ironically, the slower 2.4GHz band almost always reported 100% signal strength, which demonstrates that you certainly can't go by signal strength alone in assessing an adapter's (or a freqency band's) effectiveness.
The Rosewill RNX-N600UBE was nothing short of impressive. If you have a dual-band router, but don't yet have a 5GHz-capable adapter, this is a great way to see what you've been missing. It really is as big a jump in performance as was offered by 802.11n/2.4GHz over 802.11g. Consider it essentially a new generation of performance. If you don't yet have a dual-band router, consider buying one! Just don't upgrade to the N600UBE thinking it will improve performance signficantly over less expensive adapters when using a single-band 802.11n router.
The Rosewill RNX-N600UBE is available from Amazon for $29.99 with free shipping, as of our publication date.
[Update: After about a year of being our go-to adapter, the N600UBE got tossed into our parts bin, due to a lack of working Windows 8.1 drivers. If you're still on Windows 7, this is a great pick, but otherwise, look for something newer. We've lowered our review score from 5 stars to 3 stars as a result of the incompability.]