Definitely compare pricing. My current TaW offers are $40 off 3 day hoppers, Get 5 hopper days for the price of 4, then $45 off 6 or 7 day hoppers, and $55 off 10 day hoppers, but as someone said, they vary between employers at times, too.
I've never used them for Disney, but I've used them for Hersheypark, touring/museum tickets, hotels, and shows.