After a lot of years with magnums, here's what I have decided generally works. "Generally" meaning most people fall into one of these camps, but of course there are exceptions:
1) For long strings of untimed fire, or for a shooter with a weaker grip, get a squishy hogue.
2) For long strings of RAPID fire for a shooter who needs to compete, get a harder-compounded rubber from Pahmayr.
3) For carry or plinking for a shooter with a well developed grip, get smooth wood.
Checkered wood - not really good for anybody with magnums unless it's just carry or plinking like #3.
The various physics involved are that soft rubber deforms under the hand and against the frame, even with a strong grip. It's comfortable, but requires re-adjusting the grip or shot after each individual shot.
Harder Pachmayr rubber like on the Gripper Pro model, etc. minimize this while still providing adequate deformation/recoil reduction to make them less painful. They don't offer the comfort of the Hogues, nor the control of the wood, but they split the difference nicely.
Wood looks good, and for a few quick shots provides maximum grip and rapid accuracy. They get very fatiguing very fast, though. Wood grips, like the combat models, that cover the back strap are a little better than the exposed back-strap target or Magna models.
I use smooth wood on mine because it looks sexy, and with full magnums I only shoot a few rounds. for plinking I use .44 special rounds. If I were shooting lots of magnum I'd go to pachmayr gripper's.
LeadCounsel: as a tribute to the 4th and your service to both the country and the forum, if you pm me your address, I'll mail you a set of Pachmayr Gripper Pro's for an N frame. You like them, you can paypal me $12. If you don't like them, you can send em 'back or pass the deal forward to someone else. If you want, let me know whether your gun is round butt (post 94) or square butt so I make sure these would work for you.
