I'm not a trip report person usually, but I wrote this after our trip to MM last year. In the case of your family, though, Knott's is much more convenient.
We arrived in the lot about 30 minutes prior to opening, and were within 15 feet of the season pass gate 10 minutes later (got to use our Marine World passes), but it really didn't seem to matter if you just had a regular ticket. Would've been about 30' away in the other lines.
Day 1:
Went to X but told it wouldn't open for 45 minutes. Went to Superman, and were probably the first ride of the day. Went to Goliath which was a long walk (son is 52" so were starting with things we could both ride), and got there about 10:45. Were running 2 trains, but one was stuck on the hill as we got to load. We would've been on within 4 trains if that hadn't happened, but it took at least 20 minutes to switch on another train.
Went to Colassos (sp) and they were switching a train as well-and only running one. It was about 11:30 when we finally rode, but 15 minutes was waiting for the switch. I went to Scream, which was a 1-3 train wait for the front (running 2), and a walkon anywhere else. Rode front and back.
Went to Batman, which had only one train, but still got on within a couple of cycles for the back. We then went back to X, which had at least 45-60+ of waiting, so we bailed to see if it was on Fast Lane-wasn't. Decided to wait til next day. Got on Viper (2 trains) after about 8 cycles, and the line was shorter later in the day. Got on Revolution (2 trains) within 4-5 cycles for the back.
After lunch I went to Riddler's Revenge, it was about 3 by now, they were only running one train, and the wait for the back was an hour. After this Ninja and Goldrusher were walkons. We also rode the log ride, about a 10-15 minute wait.
It was around 5 by now. We would have taken a break earlier and come back if our MW parking pass had been good there-no in and out, or if the hotel was close enough for walking. So we called it a day.
Next morning we went straight to X, but it was over 30 minutes before it opened. We were on the 4th ride of the day, and still didn't dispatch until 10:50. Another ride would've been 45-60 minutes. Went to Deja Vu, and got on after one cycle. Got to Riddler's Revenge, and waited about 15 minutes for the front. Batman was about a 4 cycle wait. It was about one when we subjected ourselves to Psychlone, and we waited about 4-6 cycles.
After that we drove home.
I'd only been once before in 1991, and remember enjoying Psychlone, but it hasn't aged well, and the other woodie is a lumbering snore. Many hate Viper, too, probably because on sharp turns, you can really bash your head against the restraint (Hey, 6 Flags, they sell padding, you know), but I think it's a fun coaster otherwise.
Goliath has a great drop, but doesn't sustain the excitement like Desperado outside of Vegas. Still a rush to be that high and fast, though. Scream is nearly identical to Medusa at MW, which is better in the back, but Scream gets a tiny edge in the front.
Superman is OK, but the launch doesn't compare to Xcellerator(sp) at KBF. Even though Superman reaches higher speeds, it takes longer to do so. However, if you have to wait a long time, this queue has great air conditioning. Ninja and Goldrusher are fun rides through the trees. Revolution has that as well, but has a few too many lulls to be more than historically interesting. Deja Vu is a great out and back with vertical hills as it's distinctive gimmick. Hard to choose between it and Invertigo at Great America, whose gimmick is facing seats.
IMO, the 3 best are X, Batman, and Riddler's revenge. The stand up near us at Great America has never been more than an afterthought, but RR is wonderfully ecstatic. It swoops and curls through the wind with only one set of brakes. Batman starts with 2 loops seperated by an in line twist. It's very intense, full of lateral G's, and the height requirements seem to be on the honor system, as my son was able to get on it while I was riding Scream.
X takes you up a hill on your back, then into a small (10') dip before spinning you face down into a sheer, perpendicular to gravity drop. About a minute later it stopped. I'm not really sure what happened in between, although I'd like to find out someday.
It never seemed crowded, although I often felt old. Most there were 12-25 years old. I had worries when someone cut into the entry line just before they opened, but other than a group of guys with limited vocabularies behind me for RR that were on the phone inviting their friend to just cut through and find them, I only had one person "excuse me" their way through at the log ride shortly after we got in line for some people not far ahead. It's a big place, but spread out for the most part, with a lot of shade, especially around Revolution.
They have souvineer bottles you can refill with soda for $.99, or Icee's for 1.99. They cost $7.99, but you can get them with a meal (well, burger and fries) for only about $1.50 more.
My last tip is if you like peanut brittle, check out the candy shop in the back near Deja Vu.
Cheers.