E-MU made its name in sampling - the very first hardware Emulator appeared in 1981 - so you’d expect its software version to deliver. And it does: it’s a brilliant sound design tool, and even comes with a feature (called Synthswipe) that automates the process of sampling your favourite instruments. There are some great-sounding filters, plus the expected collection of LFOs, envelope generators and effects processors.
E-MU is also famous for its sound modules, which found particular favour among ‘90s dance musicians. These are represented in X3’s library - you get the full bank from the classic Xtreme Lead module. Shop around and you can pick this up for much less than the list price, making it even more attractive.