I found the stepperhead series interesting. At least one 'installment' included information on an operation I found of practical use, even if I have no intention of making a CNC lathe.
As for balance, I think taht no more than one or two long series should be in MEW at one time. It's readers don't seem to have the attention span of ME <DUCKS>.
Seriously, though, long series like Litttle Samson in ME that last some two years become like 'old friends' and can be fascinating to see develope, even when you don't build them. I think the alternating content every two weeks is what stops ME going stale.
Alternating issues in MEW is more difficult – an eight week gap between installments would be too long.
Personally I would like to see more short (1-3 page) articles in MEW, mixed with more longer ones spread over 2-3 issues.
I think the very different character and rerasdership of the two magazines is striking! If my secret project becomes a product, I shall advertise it in both mags and ask to see the readership demographics 
Neil