These companies all use "Traffic shaping", this works like a bucket with a small feed pipe. You will get an initial burst of speed, sometimes upto your limit(if the contention allows), but after a short time the bucket is empty and your now on drip feed, topping up your bucket at a fraction of your limit.
The P2P connection packets are blocked, using "socks to http" with a subscription to a socks server will get you around this.
You could also try using the "TOR" network, but they wont thank you for clogging it with P2P traffic
You should also know that your being monitored ALL THE TIME.
If you don't like the idea try using "privoxy" along with "TOR", just grab the "VIDALIA" bundle, this will encrypt all requests and responses.
Wireless would be fine for gaming and P2P if the companies had the bandwidth, they don't.
With eircom's huge charge for backhaul, and ESB getting greedy for access to their fibre the providers are tightening their belts.
If enough people complain things will change, with loads of subscribers the ISP's will be able to purchase more backhaul, so low cost crappy access is the first step, it HAS to get better.
Cisco have purchased a WIMAX company recently, the big boys are getting behind this technology, this will improve things greatly.
Hope some of this has helped someone.
Best of luck with your future access.