It all depends on what you are fishing for and what areas you are fishing in. Zoom has a great line up of plastics not just flukes. I love the versatility of the flukes for many species however. Topwater, subsurface or bouncing off the bottom. Mister twister and other plastic baits all have their pros and cons as well so don't feel like you have to get rid of them. I use the mirco mister twisters for many smaller species (white perch, trout etc).
I have been using zoom baits for some years now. I once ordered a mixture of over a hundred bags off of e-bay. My favorite is the super fluke (watermelon seed). There is a new fluke out now wth a paddle tail on it. I have a few packs of them I can't wait to try. I also like the frogs for pad beds. I will be tring what I have left this year (finese worm, centipede and mag worms). I also get a lot of action on the lizards. I have quite a few with missing tails. LOL I target bass and pickeral with these although stripers seem to like the white super fluke dragged along the bottom.
Use them both...sometimes you will want that finesse look when tossing these so put a 2/0 hook through the 3" or smaller sized flukes and watch for the results. I have used larger flukes than 5 1/4" but again it all depends on where you are putting them and what species you are going after. Stripers love these things so go big or stay at home.. I have taken big fish on the micro versions as well.