emusonacid! legacy

EOS 4.62 is the latest version that the e6400-Classic can run, so you have the most up to date version. There are 21 types of filters, and that's the most that E-mu ever programmed into the EOS.

There's a lot you can do with some of those filters, especially when changing them over the course of a sample length (but you can only modulate one filter parameter during the sample playback, the other filter parameter is only read at key-on... but if the sound is intended to be used with an arpeggiator, you can get the effect of modulating the two filter parameters as the sound plays) . They take a little more getting used to than a straight up FX unit, though. Some of the descriptions in the manual don't really suggest what the filter could be used for. It takes some experimentation to get used to how they function.

As for the FX... consider: the FX board for the e6400-Classic would cost at least around $200, IF you can find one for sale. For under $100, you can probably pick up a small multi-FX unit (check out guitar pedal effects, especially ones that feature multiple effects, if you can live without a rack mountable unit), and it would have more functions and control (more parameters, etc.) than the FX board could ever give you.