|POV-Ray Rendering of LDD model|
|Technic shock absorber|
Based on this build and others I've tried in the past, here's some of the things I've learned. Don't bother trying to build anything with a lot of Technic elements. A few Technic blocks, lift arms, and axels are fine, but once you add more than a few gears, the Hinge Tool and Align Hinge Tool start to slow down or give you really wacky results. The same goes for moveable parts like hinge plates or rocker style plates. The more of those that are in the model, the harder the program has to work to rotate them. Sometimes it's easier to break the model off into a simpler sub section to get all the rotations right, then add that sub section into the rest of the model.
LDD is perfect for building static, mostly stud-on-top models like the sets you see in Architecture, City, or those Modular buildings that are popular with the adult collectors. It's not as great for complicated Technic sets or anything that uses a lot of "unorthodox" building techniques. For example, one limitation is that LDD will only let you place bricks either on the gray building plane or on a suitable attachment point. For instance, you can place a sword on the ground, or in a minifigs hand, but you can't put it inside a barrel as if it was dropped there. This means you wouldn't be able to dump a bunch of clear studs in an empty space so that it looks like water as some AFOLs might do.
Where LDD really shines, is if you're making a model that has a lot of repetition like a mansion with a ton of identical windows or columns. In real life, it would take a while to build each individual feature and add it, but through the computer magic we all love, you can just copy and paste those bricks again and again.
Once you figure out what LDD can and can't do, it will really help you understand the possibilities of the program and give you an idea of what kind of models it would be useful for designing.