Never fished them much. Are they worth spending some time with this spring? Seems like a good bait to work through the grass weightless and let it fall in the pockets.

If I am flipping grass with plastics more times then not this is what I flip in clear to stained water. I also swim it alot around deep cover or on the edge of grass. Weightless your going to have issues getting it to drop because of the lack of weight. Some guys notch the tail to buzz it over grass. You are also going to need some light weight to get the tail to flap good unless you notch it. Manns and some other companies make a larger size that works well in the summer and around spawning beds. Gambler and Producto make a shad version that can also be killer. If you rig the shad one with a belly weight it gives it a funky fall like a senko. When bass are schooling both styles can be a killer bait. 

The key is to make that tail thump that is what is going to draw strikes. The paddle tail and the shad paddle tail also work great on a Carolina rig.

There are two Speed Worms, the paddle tail and the Ultra-Vibe. I use the latter in a variety of ways, including your way, but I see no reason why the paddle tail wouldn't do well too.

How are these rigged when they are used on the top like a buzzbait?  What kind of hook works best and how do you rig it on those hooks?

How are these rigged when they are used on the top like a buzzbait? What kind of hook works best and how do you rig it on those hooks?

I'll use a 4/0 or a 5/0 twist-lock on the Magnum ultra-vibes.  Weightless T-rig with the hook tucked into the back of the worm.  Make sure the hook enters the bait the opposite direction of the tail.  Lay the worm down flat on it's side, with the cut portion of the tail to the bottom.  Enter the hook into the bait by going up through the bottom of the worm.  Some guys like doing it the other way.  Experiment and pick which you like best.