Hi, I'm Mark Winters, the author of RideMax. I don't intend to make a habit of commenting on threads like this, because I'm sure the OP is really interested in hearing from "real people" using RideMax. Given that the WDW version of RideMax is so new though, I thought a few comments might be helpful.
We actually just relocated to Orlando in July, so RideMax plans will continue to evolve based on our observations in the parks. So for Selket, yes, we've made a number of changes since you used the program back in April.
As an example, just today I visited Epcot and observed some changes to the way in which Disney is operating the Turtle Talk attraction. These changes should make it easier to see Crush without waiting more than 10-15 minutes, and the nice thing is that we should have RideMax updated later this evening to reflect these changes. That's one advantage of actually living here now and doing RideMax as a full-time job. We should be able to keep much more current with the various changes in the parks.
With regard to those long wait time estimates you saw on some of those plans, my advice is that anytime you use RideMax and come up with a plan you're not thrilled with, keep tweaking things until you are happy. I had relatives in town last week who wanted to go to the MK, and it probably took us 45 minutes of playing with RideMax the night before to finally come up with a plan we thought would work well for us. (And the visit to the park the next day was fantastic!)
The one thing I wanted to point out which, believe it or not, was NOT a mistake, is that "Teacups first" thing that Selket also mentioned. I know I'm probably going to get laughed right off the DIS for this, but there really is a reason for that one!
You're probably wondering how is it that on one of the busiest weeks of the year (Easter week), RideMax would go against all of the "common wisdom" out there and recommend visiting the Teacups BEFORE Dumbo?
What a lot of folks don't realize is just how date-specific a RideMax plan is. When you use RideMax, you first select the date of your visit. So a RideMax plan created for a summer visit will differ substantially from a plan created for the fall. And even from one day to the next during the same week, you'll see variations in the plans, depending on the parade schedule or Extra Magic Hours (EMH) days that week.
This "date-specificness" is also coming into play with the plan which Selket mentioned, created for Easter week. The exact date of this plan was on an EMH day when the park opened at 7am for EMH guests, during a week when the Magic Kingdom hosted the EMH every day of the week. The MK even shared the morning EMH with another park on some of those days. The net results of this "aggressive" EMH schedule at the MK were extremely light crowds during the 7am EMH hour that particular week, and that is what RideMax assumed in this case.
Just how light were those EMH crowds? Well, on Monday of that week, as I walked by the Dumbo line at 8:15am, more than ONE HOUR after the EMH began, Dumbo STILL had just a one-cycle wait of about 5 minutes. And the same thing happened last Christmas week as well (when the EMH schedule was similar). In fact, I still remember visiting the MK the morning after Christmas, coming into Adventureland at 8:15, and seeing absolutely NOBODY in line for the Aladdin ride. The CM's staffing the attraction were just standing there waiting for someone anyone to show up! I literally laughed out loud when I saw that, since it was so opposite to what I was expecting during the busiest week of the year!
My point is that this plan which recommended visiting the Teacups first was only intended for use on
this specific date, when it really wouldn't make too much difference if you rode Dumbo first, or the Teacups first, or stood on your head in front of the castle for 15 minutes and counted strollers first.

The crowds were so low during the 7am EMH that you could almost roll the dice and end up with the same overall wait time any way you looked at it. RideMax still had a small "bias" to do Dumbo early, but this bias wasn't nearly as strong as it would be on a more "normal" day, when the crowds for Dumbo build much more quickly.
So, on a more "normal" day, such as today, by all means yes, do Dumbo first! On this particular date back in April, though, you might have actually had more fun doing as RideMax suggested and visiting the Teacups first, while everyone else headed to Dumbo.
(And who knows, that souvenir photo of your family all alone on the Teacups might have made for some nice memories someday!)
Of course, if anyone does use RideMax and has questions about the plans it produces, please feel free to email me directly and ask!
Regards,
Mark Winters
RideMax