Weight is the important factor for aluminum boards. It feels like you are typing in a solid surface. You also get fuller sound from the board without the hollowness present in plastic boards.
This aluminum board is also gasket mount, compared to tray mount, which gives a more pleasant typing experience.
right now i been using an aluminium board, the keychron q3.
But i believe for for the thock sounding of keys, plastic boards provide that more thocky sound after adding in the necessary foam mods compared to Aluminium. of course it depends on the keycaps and switches but somehow i notice plastic boards give off that more thocky sound.
like for example the Aula F75, its plastic, cheap, and comes prebuilt with 5 layers of foam..it sounds good out of the box. saw the pricing can be like only $30+ sgd if buying in taobao with all the coupon codes for first timer haha..
The Aula F75 also has a weight to it according to reviewers due to it coming with all the prebuilt foams and paddings. Of course cannot match with aluminium's weight. But as a user of both plastic and aluminium...to me its just a weight thing. Apart from paying more for the material, other than that, what matters is the board, keys and switches ya. Aluminium boards also have that pinging effect so have to do some mods to clear that pingy sound.
Currently alot of craze for the Aula F75. all over reddit.
An example, see the comments. those who prefer alum boards, tried out the Aula F75 plastic board and was very well please.
Since its so cheap in taobao, i just ordered one with my wife's tb account haha... gotten it in this black colorway.