We originally booked our trip through WestJet. I would not do it again.
They charge you a fee (I think $75/person) for any changes to your reservation. We wanted to upgrade from a value to a moderate, they would do it for a $150+tax.
A few weeks later I found I could get the flights (through travelocity) and the reservation for hotel+dining+tickets through disney for less money (including cancellation fee) and we would be there an extra day.
We decided to cancel the westjet vacation when we called they said they would cancel all but the Magic your way tickets ($1000) were non-refundable. It is written in the agreement, (we found out later) but it is hidden in with other information no where near the cancellation information. We had called WestJet the day before to make sure that the only fee that would be charged would be the $75/person, and the rep said yes that would be the only charge. There was no mention of non-refundable MYW tickets, and she brought up our reservation in the system when we asked.
While we were not happy we said fine we would take the Magic Your way 7 day tickets and cancel the rest. That is when they told us that while they are non-refundable they will not provide them outside of the package. So you have to pay for them but they will not give them to you.
After many calls we finally found a manager who agreed to refund the total.
So based on my experience I would not book the package through WestJet vacations.
There also some benefits with booking through disney directly you can change your reservation with no penalty(I have read sometimes they will charge you $10) You can also easily book your ADR's online now and do online check-in.
Check flights out of Bangor or Portland you can save lots of money if you want to fly out on Maine.