absolutely not, your downlaod speed is only dependant on your ISP, since 3mb is the top speed u got available, a wifi router can only eat it up a bit... never increase it... i suggest if your modem is laso a router to hook the catcher directly to the modem and bypass the apple extreme...
i got one too
The primary factor that influences remote viewing quality over the internet is the upload speed at the Slingbox.
If you're viewing over the LAN within your house, your DSL speed is irrelevant because the stream never needs the internet and doesn't leave your home network- at that point you're talking about routers, network load and internal performance... a separate issue from what I think you're asking about. I'm assuming you are trying to increase remote viewing quality somewhere away from the Slingbox.
Put simply, the Slingbox is uploading it's stream, the Player (or SlingCatcher in your case) is downloading it. The maximum bandwidth available for slinging is dictated by how fat the pipe is on the originating side with the Slingbox. More sustainable bandwidth = Greater quality. It's as simple as that.
Since most home broadband internet service has substantially faster download rates than upload rates, poor viewing quality over an otherwise completely functional link is almost always caused by the ISP connection on the Slingbox side.
www.speedtest.net and www.dslreports.com/speedtest are two good places where you can check your speeds.
Slingbox does a very good job of stuffing the best quality it sustain up whatever bandwidth is made available to it. More is better though, especially if you have a big TV connected to your Catcher.
Regarding your AP Extreme: that's just a router, nothing particularly special about it when it comes to slinging. If you have set up a WiFi bridge between your SlingCatcher and router, you may find that it eats up some of your network performance. Slinglinks powerline adapters are usually faster than bridges, but very costly. An ethernet cable is the simplest, fastest, most reliable and cost effective way to connect your Catcher to the router. If that router happens to be an AP Express, nice ! Those are pretty cool. But it's not going to make things go any faster or help you get a better picture.
Regardless of the link between your Catcher and router- or your DSL speed at the Catcher's location- the bottleneck is still going to be the upload speed at the Slingbox. Check there first.
Hope this helps !