I have Monitor Audio RX Silver, but upgrading to Pioneer EX Series

Hi everyone

I am the proud owner of the following setup:

- Pioneer SC-LX90 AV

Speakers: Monitor Audio RX8 (Front); RX6 (Back); RXCLR (Center) and RX-W12 (Sub).

However the speakers that were always in my mind were the Pioneer EX Series....i've read also a few reviews comparing these to the B%W 800 Gold Series.

I have my setup in a rectangular Home Theater Room (6 meters by 5 Meters) and i have an offer from my dealer to trade my Monitor Audio for the Pioneer for the following setup:

Speakers: Pioneer S-3EX; S-4EX, S-8EX, SW250S

THE DEAL: I MUST PAY 8000 EUROS + MY SPEAKERS THAT AR IN BRAND NEW CONDITION.

My doubts are many....Will i notice a bid diference?

The RX-W12 Monitor Audio Sub is a 500Watts with 1000Watts peak, i feel like the Pioneer S250S will be a "dead" sub compared to mine....

Any good advices?

Tank you

Tank you for your opinion.
I would like something with quality but with good appearance....no ofense.

I love how the Pioneer look, B&W...etc...

A dealer also offered me a full set of Klipsch THX Ultra II for 5000 Euros, it's a great price, but i really don't know the level of quality of these speakers...