In reply to steveshaking:
Yeh, looks like they've just managed to be much more consistent in expansion range:
Size . Expansion ratio . Improvement
........ Tech ..... Helium
0 ...... 1.4615 ... 1.6071 ... 9.96%
0.5 ... 1.4118 ... 1.6099 ... 14.03%
1.0 ... 1.5263 ... 1.6098 ... 5.47%
1.5 ... 1.5217 ... 1.6100 ... 5.80%
2.0 ... 1.5172 ... 1.6096 ... 6.09%
2.5 ... 1.6667 ... 1.6102 ... -3.39%
3.0 ... 1.5349 ... 1.6103 ... 4.91%
3.5 ... 1.6078 ... 1.6099 ... 0.13%
4.0 ... 1.5625 ... 1.6100 ... 3.04%