We love DL!!!! Our supposed to be one family trip years ago so DD could see the Aladdin show before it closed (which Disney changed their mind after announcing the closing and it is still there), turned into an annual DL trip. Get hoppers! As someone noted above the two parks are right next to each other. All that separates them is a plaza- the walk is shorter than going from where a WDW bus drops you off to a park gate. Also bag check is on the outer edges of the plaza, so there is no bag check to slow you up going from park to park. You can literally get from the back corner of one park to the back corner of the other in 10 minutes- we have done it!
No huge planning required for DL- which is one of the things we like about it. The old FP system is still alive and well. Dining reservations can be made 60 days in advance- but things won't fill up that early. It isn't too hard to get reservations most places. The CS in our opinion is better than most in WDW, so you can easily do without TS.
For World of Color, which is fantastic, we do the dining package. Then we take ponchos and put ourselves right down in the wet zone (depending on which way the wind is blowing- you can get wet). We usually go get a spot around 45 minutes before the show. The other prime spots will go a little earlier, but the wet zone usually takes a little longer to fill up. Everyone stands for the show and I am short, so I like to be down front where I am not blocked.
Fantasmic is better at DL than at WDW, but it takes a pretty big time commitment. There is no auditorium for it like at WDW- so people stake out spots hours ahead of time. In the off season, it only plays on the weekend, so you may not even get a change to pick that up depending on what days you go. We like to splurge and do the Fantasmic dessert package. That books 30 days in advance, and it can fill up really quick. With that, you get an actual chair. You get a box of desserts, cheese, fruit and crackers, and unlimited soft drinks, water, coffee, hot chocolate etc. If you do the first Fantasmic, then you get to stay in your seats and watch the fireworks (not with a castle view, but we still like it). One person in your party does still have to line up ahead of time to pick your seats (there are 3 rows), and how early depends on how much your care about what seats you get. I will say that if the 1st row is gone, then pick the 3rd if at all possible, because in the 3rd you can scoot your chairs back and even stand up if someone in front of you is blocking your line of sight. We make the mistake of picking 2nd row in the center once instead of 1st row on the edge- big mistake because we got the big and tall family in front of us- I swear there was no one in that family that was under 6 foot 3! Won't make that mistake again!
If you like shows- even for a short trip, the Aladdin show is well worth the time commitment. It is the best show I have ever seen in a Disney park. It is about a 40 minute show, and it is fabulous.
Radiator Springs Racers is far superior to Test Track. Also, if you get a chance to ride it at night, it is amazing after dark. If you get a chance you should see Carsland after dark too. For RSR, there is kind of the old TSM FP run and the line generally stays long all day. The FPs will run out pretty early in the day, so you want to be sure and get there. But, there is also a single rider line. We rode it multiple times using that line on our last trip.
You will find posts on all of these things and more in the Disneyland forum!