Looking to add some DB6 to an existing setup but had a question

I had a question before I purchase the Definitive Technology BP6 speakers. I have an existing Onkyo HTIB setup that I purchased about 2 years ago. Its an ok system and want to upgrade the speakers pair by pair. I can get a good deal on the BP6s and was wondering if it would be noticeable difference if I replaced just the front onkyo speakers with the BP6's. Is it worth getting them? The next step will be getting a DT center speaker just to let you guys know that I will def be changing the center speaker. Im just getting a fairly good deal on a pair of DB6s so I wanted to jump on the deal. Any insight would be much appreciated. Thanks in Advance!


And also, its for a home theater room setup for movies.