Are the 12 inch jelly worms good.  They are some of the biggest worms I can find and they look like a huge trick worm.

Sure they are.  Go big or go home...

I have been using them with great success for years. My Favs are the Grape(purple) and Marmalade(Motor Oil)

They are nice i use um the 12 inch ones are big but i have caught 3 pounders on them ,its ironic i caught my biggest bass (10-4) of all time using a manns jelly worm and it was a 8 incher in grape   after using 9  and 12 inch worms a few days before that same area even using auger snakes same size. MANNS makes great plastics and hardbaits....

I haven't used the 12 inch worms much, but I absolutely love the 9 inch worms, and I don't see why the 12 inch ones would be any different.

The jelly worm is probably the best worm on the market imho.  I can catch more fish on them than I do any other worm.

I haven't used the 12 inch worms much, but I absolutely love the 9 inch worms, and I don't see why the 12 inch ones would be any different.

The jelly worm is probably the best worm on the market imho. I can catch more fish on them than I do any other worm.

 I catch less dinks with the 12 inch, although it is amazing how smaller bass will nail it also

 For me larger worms seem to work better in weed, perhaps there is more worm for the bass to zone in on.