Well, I cashed in my voucher and I couldn't be happier (well, I will be happier when I am in CR). The process was a bit awkward so I will explain so those that haven't done it can be reassured that it works.
1) The voucher covers everything including taxes and all fees.
2) You make a reservation and get your record #. Don't pay, just reserve. Since the system only holds for 24 hours, you need to call them.
3) Tel # 800-433-7300
4) Skip all the computer voice crap and just say agent.
5) You would think with the identification number on the voucher it could all be electronic. Nope, you need to send it in. I made a copy just in case.
5) On the outside envelop, you need to put your flight # and record # under your return address.
6) They will give you the address.
7) I was able to book two different tickets. I had to $54 dollars on the second ticket to cover the remaining balance (2 X $277/ticket = $554). If you only use part of the voucher, they will send the remaining balance in another voucher.

It takes about a week for them to receive the voucher and send you a confirmation email.
My first trip is 1/13 so I think if you book 1 month in advance you should have no problem. The second trip is 3/3 so I can party with Nhhank.
Nh, first round of waters is on me.
Dean