I'm currently using NGUI to do draw all my particles and effects in my game and it works very well.
It's great because I could literally fill the screen with thousands of particles and it would still only cost 1 draw call!
An issues to consider is depth sorting. You'll need multiple panels depending on if you want you particles to appear in front of or behind objects. My scene is fairly static (arcade board game) so I got away with only using 3 panels, 1 for front, 1 back, and 1 for UI. The other is the number of atlases you may end up needing to use, based on your material type requirements.