I really like the IQ5's (mine aren't the SE versions though), they sound great, but I would admit I felt that the addition of the sub was necessary (The SW150 is so much fun, you just can't help turning it up).The IQ6c is a recent addition so I'm just getting used to it (also it will need some time to bed in, the IQ5's did). I used Sin City to test out the centre, the sound is really great, and dialogue really shows what you get by adding a centre. I'd probable recommend teaming the IQ6c instead of the IQ2c with the IQ5's as I think it's gives a better fit.
Piper : Huge TV, small screen (28"). We will probable have to wait until the CRT dies before getting a HD (can't justify getting rid of a working TV), so were inviting any friends with small children round, in the hope one will stick some toast in it 😉