If you upgrade to FS-UAE 2.4 beta, you can install fs-uae:i386 at the same time as fs-uae-launcher on 64-bit deb-based distributions!
http://fs-uae.net/download-betaAs has been noted already, the uae_cachesize option must be used to enable JIT. While JIT will make the A4000/040 model run substantially faster than without, the JIT/fastest-possible support in FS-UAE isn't really optimized yet, so getting a somewhat "faster Amiga" when using WinUAE is to be expected.
