This keyboard uses a special mechanism, so thewhich makes typing feeling is very nice.

To make it sound more casual/natural, you could say:

It’s got some special mechanism that makes typing etc...

It’s got this special mechanism etc..

Additionally, my laptop's keyboard I've used isthe keyboard on my laptop I used to use had a Japanese-layout, but themy new one ishas a US-layout.

I’ve realized that the US-layout was easyier to use, especially when I type in English.

You could also phrase it like:

I’ve been noticing that the US-layout is easier to use, especially when I type in English.

When it comes to the Japanese-layout, there're unique keys used in Japanese, such as tothat change hiragana/ to katakana or toand convert hiragana into kanji.

BesidesAlso, the enter key is bigger and its shape is almost square.

So,This makes the layout isn't unsymmetrical and, which I think it's a bit inconvenient.

There’s nothing wrong grammatically with the way you phrased it and it doesn’t sound unnatural or anything, but if you say it like this I feel it connects better with the previous sentence.

I also consider the US-layout is better for programming because you have to/it'’s neededcessary to type alphabets and signs, for instance,(Latin) letters and signs, like semicolons or parentheses.