Time capsule vs Linksys WRT1900AC

If you look at a comparison.

eg http://www.smallnetbuilder.com/lanwan/router-charts/bar/113-5-ghz-dn-c

You will see the Linksys is around twice the speed of the TC.

BUT that is measured to a client device made by Asus with windows drivers.

I doubt anybody in the Apple world has done proper testing of the two.

Wireless is not like ethernet where one result fits all.. we are talking about wireless .. a technology more akin to voodoo than science.. what results you get will vary from machine to machine and drivers and OS and client antennas and everything you can dream up.

If you are buying for apple clients the Apple routers will give you the least trouble.. with the least abilities.

Speeds close up are probably going to be comparable.. speeds and precisely what you mean by that.. otherwise will depend hugely on the environment.

Does your comcast service come with a provided modem, or do you have to buy your own??

If you have a modem, you do not need to buy another one.. if you have no modem and one is not supplied then buy your own.. it is usually cheaper after 12months to buy than rent. Comcast will have a list of compatible modems you can buy.. please buy one from that list but I would shy away from the Motorola.

Plug the TC into the modem, as per the setup guide you can download. Run through the setup utility in the airport utility and it will work fine for AppleTV and Roku and whatever other wireless or wired clients you have.. It is more than enough for your needs so you do not want or need the linksys.

The comcast router is all you need for router function. The TC will be in bridge mode.. plugged WAN port TC to the LAN port Comcast Router.

Bridge will be like this on the network tab.

You will create a wireless network.

You can name it as you like but I recommend short names.. eg TCwifi

Use WPA2 personal security and set a password. 8-20 characters depending on your level of paranoia.. pure alphanumeric.

You can also use an identical wireless name = SSID and Security / password as your comcast router.

It doesn't really matter which wireless clients join to.. you need nothing more than this at least for now. And you can run your TM backups to the TC.

The TC and the Linksys are about equal. As I tried to indicate in the first post.. your question is so dependent on environment that it is meaningless.

For mostly apple clients the TC will generally work better. For PC and other clients the Linksys should be at least equal or better..

So in your case which is the more powerful is almost irrelevant.