Time Capsule: Extend or WDS?

Is your existing network 802.11n-only? Do you have any wireless devices that aren't 802.11n (like an iPhone or game system)?

extend and WDS are basically the same thing.
the W in WDS is wireless.

although you can wire them just don't use WDS.

if the TC is the "remote" base (AE is the main base)
on the TC, use the following settings (or AE if it's the remote)
-under wireless
--Create network
--same SSID and security settings (password & type) as the main base
--different channels (although automatic should take care of this for you)
-under Internet
--set connection sharing to "off (bridge mode)"

with this setup, your devices will roam between the 2.

or like aristobrat asks, if you do have a mix of b/g and N equipment.
wire the AE & the TC.
set the AE to N only with ssid of myNetwork-N
set the TC to B/G with SSID of myNetwork-G
set the TC to "off (bridge mode)" like above



and currently on a properly functioning system, wired should always be faster. and is defiantly more stable (my wireless has problems when i run the microwave)
so if you need to do a big backup to the TC, make sure there is a hardwired connection between you and the TC.