Hachi wasn't as bad because, while it lasted for a while, there were actually interesting things that happened during that fetch quest that made it worth reading weekly.
I'm sorry but stuff like: Hachi goes to kick ass of octopus, He was tricked, Guys floating in the water, Wrath of Hachi, Hachi Was Wrong, Back to the Octopus, that's 7 weeks right there of backpeddling. Ugh. Different strokes for different folks definitely applies.
The Enel story was pure blandness up until the final parts.
I was waiting for more payoff. An explanation of the doctor's knowledge of such devices, elaboration on the space pirates, explanation of the separation of the wing issue, etc. Basically stuff that would have made all the piddling shit along the way (ie. Ener takes a step, Ener takes another step) really interesting in restrospect.
Didn't happen.
Hachi pissed me off for being long, being about a character I wasn't crazy about, leaving the rest of the Arlong crew untouched and having no major cross-overs with the story. Ener was just bland although I'd enjoy it on a quick read-through.