I noticed some minor tweaks to the basic wireless settings, although I could have missed them when looking at the WRT610N. The 5 GHz radio has Disabled, Mixed (default), Wireless-A only and Wireless-N only Network Modes, while the 2.4 GHz radio shows Disabled, Mixed (default), Wireless-B only, Wireless-G only and Wireless-N only.
As is the norm for Linksys draft 11n routers, channel selection is a bit odd. Channel Width selectors properly default to Auto (20MHz or 40MHz) for the 5 GHz radio and 20MHz only for the 2.4 GHz. But when set to Auto, The Wide Channel and Standard Channel selectors are greyed out.
If you choose a the 20MHz only Channel Width on either radio, you can set only the Standard Channel. (The 5 GHz radio can be set to channels 36, 40, 44, 48, 149, 153, 157 and 161.) But the new wrinkle is the 40/20Mhz Channel Width selection instead of 40MHz only. That greys-out the Standard Channel selector and lets you set the Wide Channel instead. But once you make a Wide Channel selection, the Standard Channel selector becomes active and shows only "valid" selections.
The main problem that I have with Linksys' method is that the Wide Channel setting is misleading. In 2.4 GHz, the draft 11n 40 MHz mode extension channel is always located four channels away from the primary channel. So when the Standard Channel is set to Channel 1, for example, the second channel is actually set to Channel 5. The resulting 40 MHz wide channel has its center at Channel 3, which is what Linksys may be trying to convey with the Wide Channel setting. I would like to see Linksys show the channels that are actually being set, but doubt that they ever will.
Minor rant: I really dislike the use of "Wireless-N" instead of Draft 2.0 802.11n as a way of getting around reminding buyers that they are still dealing with a draft-standard product. I don't care much either for "Wireless-A", "Wireless-G" and even "Wireless-B". Call them by their standards (802.11g) or just use a, b, g, draft n.
The 400N supports Wi-Fi Protected Setup (WPS) and defaults to showing it when you first access the Basic Wireless Settings page (Figure 4). You have to select the Manual radio button to directly access the settings.
Figure 4: Basic wireless configuration defaulted to WPS
I tried using WPS to connect my notebook using an Intel 5300 AGN WiFi Link adapter using the Intel PROSet Wireless Connection Utility (version 188.8.131.52). Unlike other client utilities that I have used, the Intel utility doesn't support a WPS push-button method. Instead, when you try to connect to an AP, you are prompted for its Device Ownership password (also called its PIN).
I initially couldn't get a successful WPS connection because I kept pushing the WPS button on the WRT400N, even though I wasn't prompted to. But, just as I was ready to give up, I tried just following the Intel utility's instructions, i.e. just entering the PIN and not pushing the button. Once I did that, the WPS session completed with a WPA2 / AES connection and horrendously long auto-generated password. But I could have changed the mode (WPA / WPA2), cipher (TKIP or AES) or password as part of the WPS session. Lesson learned.
Figure 5 shows the Advanced Wireless Settings, which include Transmit Rate and Power settings and AP Isolation, which keeps wireless clients from communicating with each other. I just noticed that the Frame Burst control that the WRT600N had is missing from the 400N.