TBH, I rarely use my wireless dongle, if I'm on the road I use 3G or wifi on my phone to keep up to date with e-mail and the web. Sounds like a good deal on the free home wifi, especially if you're happy with it.
Prior to the Post Office I was with BT for my home wifi broadband. It was a bit expensive, but it worked 24/7 365 days, I never had any problems at all. You get what you pay for