Why isn't it a great chopper?
To begin with there's the usual confusion with the very term-"chopping".
Chopping,technically,means to cut wood Across the direction of it's grain(it's done on an Nth angle,but overall you're severing the log Across).
More casually,"chopping wood" often refers to Splitting,i.e. severing the log Lengthwise,ALONG the grain.
These are two VERY different actions,requiring different particulars of tool design and construction.
Seems like the topic starter mentioned splitting strictly,and on this count i'll not say anything,it's a personal choice.Some prefer splitting with a maul,some-with a felling axe,yet others use a froe-the difference is the Thickness of blade(among other factors),and it's more the matter of personal preference and convenience.
However,for real Chopping,such as in bucking wood(sectioning it to stove-length),or felling a tree,there's no worst tool ever come down the pike than any and all Estwing products.
The reason for it is that chopping involves two different actions-Penetration of mat'l,and the waste,the Chip,removal.
The energy from the strike forces the edge into the log,and some of that energy is vectored off sideways(-ish),to spit out the chip.(without it your axe simply Stops,as in dead).
What creates that sideways pressure is the thickness of the bevels,their shape(like the presence or absence of convexity),and the angle of their convergence.Simple physics,vector theory,et c.
In other woodworking tools the same principle applies,notably the wood plane iron,being very thin,has an extra element bolted to it-the chip breaker.
If you were to leave the chip-breaker out of your plane,the shaving will keep on creeping up the blade,till the blade embeds itself so deep as to you no longer being able to advance the tool forward,it'll become STUCK.
That is the reason why were you to earnestly swing an Estwing into the wood,the very next action then will be you rearranging all your muscles in order to start rocking and prying and Pulling on the handle to free your "axe" for the next swing.
That wastes time and energy,and annoys the daylights out of you

...(annoyance being another action Very wasteful of energy

.
An Estwing "axe" is exactly like a wood-plane with chip-breaker missing,it's practically a 2-D axe.
(in fact,once on a hunch i offered it up to an older Collins HB,and all the major points-edge,poll,handle with almost all it's curves,ALL coincided almost perfectly.Now looking at the two from the top one can really see the answer to the riddle).
Estwings are junk on several other counts,i'll not bore you with most as they're probably specific to my environment(the bush in interior Alaska).I'll mention one:The bigger,blue jobs rot off right at the juncture of rubber-coated tube handle to solid shank.
For that reason you see the broken off head&shanks around,and a number of times folks have brought them to me as gifts,being as i'm a village smith of sorts.
I use them for hot-cutting steel,and i tell you what,they're made of some Excellent alloy.
(they tell me(everyone,incl.the manufacturer)that all it is is AISI 1055,can't argue with that;but i can hardly believe how well the darn things hold up,i've used them mercilessly,driving them with a sledge through 1"+ of yellow-hot steel,with hardly any distortion of that Uber-thin edge.
I tell you guys that in great secrecy,as all this tends to hurt the Estwing-lovers' feelings to Such a degree that anymore i catch meself treating it as some Deep Dark Secret!

...Hate to rile folks up,especially before all them holidays!
Happy Holidays to everyone,Estwing fanciers and everyone else!!!
