Here’s the skinny.
The thing about the 5mb/s thing is false. I regularly get 1 or 2+ mbytes/s via some torrents, roughly 8 to 16 mbits/sec.
Second thing. Most cablecos are fiber from the node, which is a box that connects your neighborhood to the cableco’s larger fiber infrastructure. Or they should, particularly if it’s Comcast. The same’s true for your DSL provider, except it goes to a DSLAM or a Mini-DSLAM, especially if your provider’s a big name like Qwest.
Third, latency, latency latency latency LATENCY. Unless your cableco/telco is ridiculously horrible for your area, this isn’t going to be a problem, you’ll see decent latencies across the board.
Fourth, don’t count out wireless just yet. I work for Clear, a wireless provider that’s available in your area and while our latency numbers aren’t quite there yet, they’re also pretty damn decent. They’re available in Vegas too, so I’ve had the chance to play around with it. SF4 and GGPO are quite playable; however for the cost, you could just as easily get basic DSL or cable service; however, if Qwest or Comcast dicks you over, well, there’s always wireless. Of course RF coverage issues are a huge concern(poor coverage = high latency and poor throughput), but, that’s not even on the table until you count out Comcast and Qwest. In which case, well, settling isn’t such a bad thing.
Overall, go with whoever’s willing to sell you cheaper service, and if you can’t get service with either; don’t discount wireless. Unless you plan on leeching 200 gigs of scheie porn a week, or hosting 16v16 matches of Team Fortress 2, you’re not going to need faster throughput. Your basic cable package will suffice.