1st thing......take the idea completely out of your mind that you can't putt slow greens. Believe that you will hole every putt before you pull the trigger. If you have to, vizualize the hole being 3-4 feet farther away than it actually is. Slow greens break much less than fast greens, so be aggressive. It wouldn't hurt to try a Scotty Cameron putter either. Mine feels so good in my hands, all I have to do is let it do the work for me. Believe it will go in, if it doesn't it's OK, the next one will.

Just like pitching and chipping - swing speed is constant.  Control of distance is by varying length of backswing.  

Think of a 20 ft putt downhill vs one uphill.  I play mostly on slower greens. 

You are putting with an Odyssey? And you wonder why you're having difficulty putting?     get fitted for a Scotty Cameron and take some putting lessons from a PGA Professional!

Nothing wrong with an Odyssey putter.   I have a White Hot 7H mallet putter that I paid a whole 69 dollars for used and spent 20 bucks for a fitting and I putt fine with it (and truth is I putt better than one of my friends that has a $350 Scotty).   For that matter, my dad has an Acushnet Bullseye (this is a Titleist, folks)  that he has had since at least 1957 and he still putts with it today.  Dropping $350 on the latest putter or $400 on the latest driver isn't going to improve your game; work on fundamentals first.  Do the putting lessons first.

Try a lighter weight putter.

Nunzio concerning your question about slow green's .I live in the Northwest where most all the green's are poa anna grass. Anyone that has played very much on this type of grass know's what slow green's really are, especially at this time of the season when the poa Anna grass has gone to seed. I became so frustrated that I bought a new putter. The putter I bought was a Heavy Putter. I haven't compared the swing weight with my old putter (white hot ) but I would guess it weigh's twice as much .I used the putter 4 times now and I am finally getting the ball to the hole.  I bought the Heavy Putter at Sports Authorty on sale for $55. Plus tax. Nunzio I hope this helps this $55 investment has changed my putting attitude.  Good luck .  Dan D.

My first teaching pro told me that if a flat rock tied to the end of stick feels good in your hands then putt with it.

If there is something about your current putter that you really don't like then go to a good club fitter or club maker and let them talk to you and watch your stroke. 

Since you putt well on fast greens then perhaps you need to practice getting the feel of slow greens. I like to feel as if I am rolling the ball off my hands when I putt. I really don't want to feel the putter and I don't want to feel as if I am hitting the golf ball. So on the practice green occasionally I will roll golf balls with my hand to get a feel for how fast I should roll the ball. Since I try to keep the same "tick tock" pace in all my swings I need to practice the length of my back swing when I roll the ball.

My stroke is so inconsistent that I beg for slow greens!

Slow greens require a longer backswing or a faster tempo but either needs practice, practice and more practice.

Or just never play on slow greens..........