The ER6 is just a twin so it shouldn't be too expensive.
Of course, a bit cheaper in maintenance.
Only a twin, in the 'over 500cc' department, that is the thing.
It's for sure not a Ninja. It's a ER6F(airing).
'Real' Ninjas have inline4 and having max torque and power in the 5 digit rpm area. Not around 8-9k rpm ;-)
And there is no way, to compare a 600/650cc inline 4 with a 650cc parralel twin. Which ever brand you pull.
Two cylinder are having a little performance advantage, in the low displacement area, OVER the single cylinder bikes.
If it comes to 'bit better sound and more power (imho).
Example may be the Duke 390, to the R3 with 'only' 320 cc.
Two really nice bikes, made for the same riding style.
The same spec area, A2
But the little Yam. does not have to hide itself.
The Duke need the bigger engine, to keep in the same sphere.
Because of the single.
The inline2 concept, for even bigger bikes, is in my view a travel-kind of sportive-tourer concept.
They use less gas, are powerful for every need, only not the supersport type.
Did I say, I don't really like bigger parallel twins or any V2 or V4 bikes
So my pov may a little bit narrow minded.
I've thrown in the CBR500R, b/c it's a 'real good deal' bike.
I think. Great commuter, great mileage.
And still a bit sportive, at weekend trips.
But in case, the 600+cc area is the target:
Not a bike with a p-twin, please.
for me, at least.
Did ride the Versys 650, last weekend.
Not even the owner is really happy with it.
Great bike, but something missing!