As someone who works in the hotel industry just wanted to give my personal opinion/info. Third party sites are great for finding last minute rooms - just understand you will likely not be getting the cream of the crop , they are cheap for a reason. You may get stuck with the worst view - you might not , it really depends on the individual property. But if all that matters is a place to lay your head you can find amazing deals ! Just be wary is the best advice I can offer. When in doubt what amenities are offered or available call the hotel to be safe and get confirmation of a name and position so if any issues occur you can let them know exactly who you spoke with.
I have stayed at Marriott Anaheim last year with my husband as I work for Marriott and it was really awesome. Biggest downfall is the parking fees. 24 for normal and 28 per day for Valet. We went the Valet route and it was a lifesaver.
If you are flying in , you don't have to worry about the cost , but it adds up quickly if you are staying several days like we did. We actually paid just as much for parking as we did for the hotel room..lol. It's a beautiful property but with most Full Service you pay for everything - internet especially. Business class hotels such as Courtyard by Marriott often have complimentary internet and sometimes breakfast. It dosent have all the frills such as room service or a resort feel but you can save money. It depends what is most important to you and your family. Just some things to keep in mind