Thermal Expansion is a well made technology mod, and is a natural evolution to older tech mods like Buildcraft and Industrial Craft. It boasts reasonable additions to worldgen with a few ores like copper, tin, and silver. It also introduces an energy power system called Redstone Flux (RF), which is used not only throughout the mod, but is quickly becoming a standard for many other technology mods in the Minecraft community.
Many useful single block machines are present in the mod that do not require complicated setups. These machines are well thought out, in that they can operate independantly for simple tasks, but also function well together in production chains for full autonomay. Some machines of note are the Pulverizer, which is the basis of the ore doubling mechanic in the mod, the Powered Furnace, and the Slag Furnace, which provide faster and better means of smelting items.
Thermal Expansion also provides the means to transport blocks and items through piping networks called ducts. Filtering is possible on these networks, allowing for complex machine setups.