Wireless services?

[ThinkPad]

Does anyone use a wireless provider like ATT or Verison to surf on your laptop? I recently subscribed the ATT data package which came with a Sierra 875 pc card. Though it is a little pricey at around $70 a month I really enjoy the mobility and the coverage it provides.

Im thinking of canceling my Comcast internet and just using this card. I have another month to decide if I want to keep this card or not. To those who have these services, have you had any issues or problems? Ive only had this for about 2 weeks; I hope im not being over zealous, for lack of a better word, for this product.