The Trak2 has balanced line in/out which enables you to put f/x in line before A/D. In fact the unit has super-flexible routing, so you can route anything into the line-in's to hit the a/d. And with the optional d/a hardware installed you can easily route from your DAW out to f/x and back in, as well as running your monitors off the high-quality d/a and other cool uses.
These are going pretty cheap on eBay now... I just sold mine w/8DAC & ADAT for around $2200. Would never have sold it if I hadn't needed 8ch A/D, it was a great sounding box. Ended up buying a Rosetta 800.