I've got slicing on my "bank" character, and even though I'm only at <100 Slicing, the rewards have been pretty decent. In the first tier you generally make back the cost of the mission plus ~20-50 credits, but every once and a while you will crit and get a rare schematic along with the credit box. Now, I've only been selling these for the recommended buyout, but they're an easy 400-500 credit bonus over-top of what you already got back.
It's enough to keep my main in enough credits to keep his Artifice at a usable level and have enough left over to play the GTN. Personally, my opinion is that slicing should be treated like a secondary skill from that "other" game (e.g. fishing, cooking, first aid), and made available to everyone in addition to their gathering/crafting skills. Maybe reducing the crit rate or the crit rewards a bit so as not to completely bork the economy.