I was looking at buying the 3DWIFI, but noticed it is 201. 201 does not have the same corrosion resistance as 304 and is not as tough, meaning it won't hold up to shock as well. Now I am contemplating buying the 4DWiFi as it looks like it is made from 304? Can anyone share their experience with the 201 (which is on all models under 4#)? Have you had any issues with rust, corrosion, welds breaking etc.? Is it worth paying double to move from the 3DWiFi to the 4DWiFi just to get 304 and added space? Struggling with choice as I don't want to pay $1,400 on the 3DWiFi only to wish I stepped up the plate and purchased the better quality 4.