Agreed with SP.  I have the same router - Netgear WNDR3700 is the model name - and have been very happy with it.  AC is overkill IMHO right now at least.  There are some more expensive models which increase the signal range, but probably not necessary for you.  One nice thing about the WNDR3700 (and others) is that they have a USB connection for an external HD, which you can use as a cheap network file server.

AC is a wireless standard. It's 802.11<letters>... like USB 3 or what have you. The progression, oldest/slowest to newest/fastest, is like this: 

802.11A -> B -> G -> N -> AC

I assume they have a reason for using letters instead of numbers, and those letters instead of letters that make sense. AC just - and I mean just - came out; like all previous ones, the routers began shipping before the standard was approved (still hasn't been fully ratified), so theoretically there might be issues with the early ones down the road.

AC is really fast, like a trillion zillion yottabytes or something, but nothing supports it yet. Plus, as I mentioned above, your wireless network will run at the speed of the slowest member device, and frankly it's rare for someone to be running a network that doesn't have at least one B device lurking on it. The 360 is B; PS3 is G, I think. Many phones are B. A is ancient, but B is a reliable standard that was a workhorse for its time, so it'll be years before they're all gone.

So to answer your question "why," you don't need AC because it's silly expensive and you won't actually get anything close to those speeds. If you find a nice affordable AC router I'd say go for it, because it will be more powerful in general than older ones. But the sweet spot right now is N.

Various bells and assorted whistles might make one router a better choice than another depending on your needs. Some routers have more antennae; some have directional antennae you can focus where you want; some have internal antennae that might not be as good; some have boosting hardware that supposedly makes them work at longer ranges; the only thing that's guaranteed is that every router box will present you with a long bullet list explaining why it's the best one and you should buy it right away.

I'm not a wireless (or networking) expert by any means, but I know that routers are not commodity items. Some are way better than others, and some suck. But which is which seems partially dependent on house shape, devices, competing wireless traffic, and so on. Even your brand of microwave can impact wireless performance on account of electrons and quarks and magnetisms. I like my Netgear because its friendly browser-based administration tool has lots of clear explanations, and because it has been far more reliable than the Trendnet one I had before. I have a WNDR3400, probably a generation behind Botch's 3700, and it's a trooper. The only complaint I've had is that it took an immediate dislike to my Nest thermostat and occasionally they silent-treat each other. That makes me sad because a Nest that can't compare notes and talk shop with other Nests in the area is a Nest that's not optimizing your HVAC experience to the best of its ability.

I'm going waaaay beyond my expertise here - someone tell me if I'm wrong - but you may be able to use your AT&T modem (it's a modem/router combo) and a new wireless router in tandem to extend the signal. Wireless Repeaters I think they're called? I'm not sure how it all works, though. Either way, since you mentioned that house shape is a factor, you'd do well to find one that's got a reputation for signal strength. Some routers go through walls really well but can't throw a signal far; others give you bars on Pluto but get stopped by balsa wood. Routers are the frickn' wild west.

As for dual-band, this is desirable mostly because it means that the router is probably more powerful. Many (most) devices don't work on the 5GHz band and won't connect. That stinks since 5GHz is a ghost town and whoever can use it will get great performance since there's no traffic cluttering it up yet. With all your devices though, it'll be ideal to buy a router that can run many simultaneous channels (or at least two). That will help you stay organized and give you good performance.

This is so, this gigabit point. Just the other day I was pushing buttons I shouldn't push, deep in Windows, and it said my router was not giga-worthy. It's enough to make a man cry. I want gigabits.

Question, Botch: is it the same with wired as wireless? If I moved to a gigabit router, would my gigabit-capable devices run at gigabit speeds even if they shared router with suckabit-level devices, or would the whole thing ratchet itself down?

Another question: why am I asking this? I don't think Comcast's infrastructure is capable of gigas even if everything else is, and it's not like my connection is slow. Steam eats new games at three megabytes a second, what the crap am I so greedy for?

Here's a nice article on the issues on multiple devices on wireless: http://www.networkcomputing.co...../240012803

From my own personal experience of, say, downloading something via steam, then downloading something via steam while listening to internet radio, it doesn't take much external traffic to bog down your main download effort. I would, personally, hook up as much as you could through Ethernet cables, because they seem to me to be much faster, when there's a bunch of other stuff going on. This could be a factor with the cheapo linksys routers that I have. Good on durability, maybe not so much on overall throughput to multiple clients. It's also difficult to find a reputable benchmark for this sort of thing. Does anyone own a high end router?