I would say yes, it's good enough. I believe printing jewelry is what it was designed for.
The quality of the print is down to the projector you use and how you set it up. I built my LittleRP on the cheap and am using an old projector I got off Ebay for ~$50, so its resolution is coarse. I have about 60 micron resolution x and y and I print 40 micron layers. That's been good enough so far, but I haven't made any really intricate or fine designs. Unless you're starting on the cheap like me, do get a projector that has 1080p native resolution. Beyord that, you can find past discussions on this board about specific projectors and I think there are some specific models suggested on the LittleRP website.
I'm still a novice at casting and silversmithing in general, but here are a few designs I recently printed and cast in silver to try out. These have all been tumbled for several hours but not otherwise polished:
The buckyball at back-left is pretty much polished smooth (at least on the outside) just from the tumbling, while on the orb on its right you can still see print layer lines in the middle. The other pieces are generally rough and will need more hand clean-up work.
If you get a better projector you can probably get to about half the resolution of what I'm working at (~30 um x and y), which would give you much cleaner casts to start with.