Dartcraft is one of the mods that I really have mixed opinion. I would classify with other mods like EE3, Ars Magica, EE2 etc., as too cool to leave it out from SSP world, but too easy to spoil the game when abused (e.g. used efficiently). It has really good innovative features: BC pipes that do things, great worldgen with only one ore, using harder to get liquids to enhance power production, making "single use" tools specified to your needs; and some improved designs, for example all mods have some kind of bags, but DC ones combine all advantage of them in one and more, flight is my favorite one with IC2 jetpack being close second, very useful but still requires for you to make scaffolding. Of course there are some features that I really don't like: messing with TC3 silverwood balance, everything is dirty cheap which doesn't encourage designing cool systems, it is taking features too far like sharpness 10 or fortune 4, it completely replaces things from other mods with all around better alternatives like combustion engine or forestry grafter, it is really easy to make almost invulnerable armor, recycling armor or tools don't take durability into account, making mob farms even better.