Well, GetAwayToday uses The Walt Disney Travel Company, so the same basic good neighbor packages as from
Disneyland.com, though the prices might be a bit less and an extra perk or too. (Same with
AAA and Costco).
I personally prefer to do it myself, your main parts are airfare, I have frequent flyer programs with multiple airlines,like to pick a specific airport,such as Long Beach and look at the "extra charges" which usually are not part of the package, such as baggage fees.Also, as far as I know, companies like WDTC don't offer Southwest, since they don't pay a referral fee.
Next is Transportation, either a rental car, or some sort of shuttle. I have Frequent Renter cards that let me bypass the rental counters and just go pick up my car, so I can look for the best price out of the ones I prefer.
Then we have the specific Hotels, once again I have Frequent Guest memberships, and most Hotels now promote a "lowest price" guarantee if you book online at their website, since they don't have to be the referral fee.
I also like to not just do one thing, such as all Disney, i do want to check out other places, and there are multi-park discount programs that give you a discount, such as the SoCal CityPas and the Disney/USH combo tickets. So going to places like Mousesavers is what I would do. Also, more and more parks (and other things) work on Surge Pricing,where you can get a lower price if use the directly and pick a slower date. The Park's website show those prices on a calendar (such as Disney and Universal), so I can see that if I opt for that Thursday over Friday, i could save some money for planning purposes.