Reading last month about new, improved Wi-Fi routers incorporating draft 2 of the 802.11n technology spec (see "New Wi-Fi Draft Ensures Compatibility") reminded me of a pet peeve I have about shopping for tech products: Vendors don't always make it easy to know exactly what you're getting.
For instance, D-Link released one Extreme N Gigabit Router that is based on the original 802.11n draft and may have problems connecting with other 802.11n equipment. Then the company released a second router that is based on draft 2 and is far likelier to be compatible with other manufacturers' equipment. But good luck figuring out which one is which. The first model is called the DIR-655; the second, the DIR-655.
The good news is that original draft-n products are firmware-upgradable to compliance with the second draft. But if you buy an older product, it's up to you to figure out whether you need a firmware update. Generally, if the packaging lacked a Wi-Fi Alliance logo specifying 802.11n certification, you'll need an update.
Looking Under the Hood
At least the draft-n changes affect only firmware: Sometimes vendors tweak the hardware innards of products without notifying customers. Case in point: Sony made more than a dozen versions of its popular PlayStation 2, including some that looked identical but had different features. For example, Sony dropped an IEEE 1394 port in later versions while adding an infrared port for an optional DVD remote. You could tell which model you had only by inspecting the unit or its model number (which appears on the back of the PS2, by the serial number).
Sometimes the specs don't change, but the components do. PC vendors that buy system components in huge quantities may use different suppliers for, say, optical or hard drives over the lifetime of a single desktop or notebook model.
A Dell spokesperson confirmed this practice but said that all components must meet stringent specifications. So even if the model PC World reviewed isn't identical to the one you buy, the spokesperson said, your experience should be similar to ours.
My own experience has taught me that this isn't always true for all vendors. My last notebook, an IBM ThinkPad X31, had a built-in Wi-Fi card that usually worked fine but refused to work at all with certain newer Wi-Fi routers until, with a Wi-Fi engineer's assistance, I tweaked an obscure default router setting. The engineer told me IBM used that Wi-Fi card for only a short time, so the problem was rare.
You can't dictate how vendors label their products, so you have to educate yourself before you shop. Find out what's happening with the technology, especially in a field that's changing rapidly.
If you see a price cut, try to determine whether the retailer is unloading older, outmoded technology. Be especially careful when shopping online, where you don't have access to visual cues that you might get by inspecting packaging.
And if you aren't getting enough information, don't be afraid to ask for help. You have a better chance of finding answers while you're still a prospective buyer than when you return as a disgruntled owner looking for tech support.