have had reasonable success on the prawnstar - caught Jack, Flathead and Cod using them. but for some reason they are not a lure I choose to use first, but rather an after thought? they claim to be relatively snag free, which is also a bonus when chasing Jacks
as for sp's at night - they definitely work, but you need to be in the right spots. try areas where bait will congregate, particularly around light sources like bridges, etc. you may find the sp's with more moving parts (ie shad tails, etc) will work better than others (ie jerkshads, etc)
marty