Don't confuse heavy FEEL with heavy keyboard...

Basically, as far as comparisons go, most arrangers have almost the exact same feel, at least compared to the wide range of other keyboards, from stiff old piano actions, to toy keyboards with no weight whatsoever.

There's far less difference between my G70 and a T5 than there is between different pianos alone!

But the construction of the CASE? That's where most of the weight differences between arrangers is coming from. And, unless you only play at home, cover up your keyboard with plastic while not in use and baby the switches and knobs, that's where you are going to see why stronger, hence heavier construction comes into play.

Now, I know on this forum of rabid equipment changers, few of you ever keep a keyboard more than a few years. But keep it ten years or more, and you will quickly see why a little extra weight pays off in the long run.

TBH, I have doubts my BK-9 will hold up nearly as long as my G70 has. Sure, lugging 25 fewer lbs around is going to be nice. But ask me again in ten years!