If you are planning on travelling on US Airways any time after March 1, my best advice to you is to NOT use an E-ticket.
In most situations, attempting to use an E-ticket on another carrier is almost impossible. The new carrier cannot look up the details of the ticket. When using a paper ticket, the new carrier has a written record of the cost, class of service, and dates of travel.
The bottom line, paper tickets might be a hassle up front, but if your flight gets cancelled, that paper ticket might save you hours in line at a ticket counter.