That Orbea certainly is sweet loooking! A couple of things to note about mountain bikes vs. the hybrid that you currently are using:
1 - Mountain bike bars are often quite wide for maximum control. Do you have any narrow gaps on your commute?
2 - Mountain bikes are usually specced with longer crank arms than road or hybrid bikes. You'll notice it if you're a spinner.
Also, that Thudbuster will no doubt smooth out the ride but the Orbea has such clean lines that it'll look like a roof rack on a Ferarri. Someone else mentioned a cleaner suspension seatpost. I'd recommend that, or just try it without a suspension seatpost at all at first and find a tire pressure that rolls and if comfy.
Best of luck. Be sure to post pics and a ride report when you get it!