For LNC2s with straight legs and itty-bitty grocery-cart type wheels:

 

Which are best?  Anything but the donuts.

 

Although this has been gone over before here is a bit of history:

 

1.  Early donuts were so-so unless the airplane was parked outside in the winter - then the donuts could take a "set" and the middle gear door wouldn't line up properly upon gear retraction.  Bummer.

 

2.  Ergo, the later version of donuts were harder (stiffer) and, as Chris observed, "the tire took the landing shock."  Worse yet, the landing experience included a "skittering" effect, especially in a cross wind and a feeling that directional control just wasn't there.  It seemed as though the tires never got a grip on the runway.

 

When a dampening device replaced the donuts, the difference was astounding.  Like a good suspension system, the landing shock is not only absorbed, but the tire is kept in contact with the pavement resulting in more control.

 

Since we have learned or will learn that all aviation things are part of a system and a part change may affect the system, think on this:

 

1. Spry's springs are heavier than the donuts whilst the DeBongers (TK5s) are lighter.

 

2. TK5's stiffness is adjustable (nitrogen pressure), I don't know about the Sprys.

 

3. Upon failure (damper pressure), TK5s will bottom out, Spry springs probably won't but you may be subject to undamped springs.  A failure will affect the AOA as the plane settles on the runway.

 

4. If the TK5s are set too soft, a heavily loaded plane will have a pronounced AOA such that seeing over the nose is impossible.  More importantly, upon landing the mains may settle more than is desirable and, if the landing speed is too great, the flight regime will be re-entered.  On the positive side, the 70" prop is further away from the ground.

 

I have over 550 landings in at least 5 years on the TK5s without a failure.  Some landings have been too fast, some have been too "firm" but the TK5s have always performed beautifully regardless of what silly landing experiment I was trying that day.