Depends on what you are trying to do. Like many, when I had a HTIB system, I cranked the side surrounds to hear lots of surround sound directly from the speakers.
However, as my system grew and I learned more, I learned that if you correctly calibrate your system so that all speakers are equal, that you not only get surround sound appearing from the speaker itself but all of a sudden, it can appear to be emanating from almost anywhere in the room.
If you think of the stereo effect up front, (meaning sound just doesn't appear to be coming from exactly the left speaker or exactly the right but can appear to be coming from anywhere in between,) producers also mix their surround sound effects to do the same between the front speakers and the side surrounds and rears if you have them and there is a 7.1 track.
If properly calibrated, a plane flying over doesn't just suddenly switch from the front to the side speaker. Instead, you will hear the plane in the front and the plane will literally travel through the room inches at a a time from front to side to back, giving you a much more realistic and 3D experience.
Opinions may vary, but around these parts the general consensus is that bi or quad-polar speakers are very good at creating an enveloping sound as side speakers. For rears, some people like a bit more direct action and go with a directional speaker in the rear. Yours is the first time I have heard someone say they might reverse this.
My suggestion is to try calibrating your speakers first. It's fun and meters can be had from just 20 bucks up. It will take you a while to get used to what you might mistake as "less" surround effects" but in quality mixed movies, you will get even greater enjoyment when sound starts coming from all parts of your room, not just the speakers themselves.
Examples:
One of my favorite demos to watch peoples's head turn as they follow a particular sound as it does a slow but complete 360 around the room, is in the the 'extras' video track of "only" on the Nine Inch Nails DVD called "Beside You In Time". Reznor mixed this version of the song in 5.1 and obviously spent a lot of time playing with the placement of the various sounds in the song. This particular sound effect crawls slowly around your room like a bug on the wall.
On the movie side, in one of the early scenes of "Master and Commander" when the camera is moving around below deck... you hear someone walking or something above deck and the sound actually appears to come from the left part of my ceiling. Totally freaked me out the first time I heard it as not only was it in between my fronts and my surrounds but it also 'appeared' to be coming from above.
In the end though, do what makes you smile.
