Mechanical keyboards are like guitars, you can play the same notes on a cheap one as you can on something custom made for you for thousands. Do they sound very different? Almost always, although the guitar needs someone who can actually play well, unlike the mechanical keyboard.

However, if you really really care and you really really know what you want out of either you can tweak absolutely everything about both. You want ultra soft silent keyboard? Sure. You want the most clickty keyboard with tons of pressure? Sure. You want something thocky but still has lots of flex? Sure.