We use the ATT HTC One Android with the personal Hotspot. ATT has several options for using wifi on their system. The HTC One Hotspot is only one authorized option plan.
5g for $50, which is less than my older USB card. I use the Hotspot for 2 pc's, a kindle and an HTC Desire Android Phone. If we upload pictures, at times we can exceed the 5g by 1g or 2g on rare occasions. As we fulltime, the extra $10 for 1g, is still less than the former usb card charge.
Usually we are able to use local wifi at times to offset the ATT data plan.
Been using the personal hotspot for about a year and a half. No need to go back to another device. It works good even with a one bar signal.