Tuna,
I would agree with John on the Aluminum Gear Durability advantage, at least when it comes to vertical drop. However it is my opinion it may not take as much horizontal force (mainly fuselage attachment)(But then you may be upside down before it breaks). I designed and built my our Landing Gear that is similar to the Highwing LLC, Kitfox Bush and Airdale Landing gear and performed my own drop test and found the maximum drop I could safely attain was 5.5 - 6.0 inches without fully compressing the Die Spring. The 3/4" axles are the week point. My calculations showed I could bend the axles at 4" drop but was happy to find they did not bend (may have been stronger than min. yield for normalized condition and geometry changes are hard to analyze with tire contact. The gear does have a Super Cub/Waco Look though. Here is a link to my Drop Test if your interested. You should notice the tires did not provide any cushioning in the test.
Dave

http://www.youtube.com/watch?v=fvQtKQ5gHVY