Hi, just wanted to update this thread with my experience. I used LMT 1.5 years ago and it worked fine but I did have to request the voucher several times and was very confused about the process (wasn't sure there was supposed to even be a voucher). All in all, it worked in the end and saved money.
Well we just booked for our Thanksgiving trip so I went online to LMT again to order tickets last night and did so at 9:00pm and by 8:00 this morning I had the actual voucher sitting in my inbox! I was so surpised, I hadn't expected it that quickly, but now I knew it may take a couple weeks. It clearly states on the voucher to redeem it at the ticket window for your tickets.
Very happy that this was such a simple process this time and hope it helps somebody else save money on their tickets as well!