Hey, you are not alone in two-channel land. I once had a roomful of speakers, but I was never happy because they were all different models, although the same manufacturer (Polk). My amps and speaker cables didn't match, either. I figured I had a better chance (with my budget, always a consideration) to achieve more coherence in the soundfield by going to 2.0, although I have since added a subwoofer.
I have used an aiming technique that I learned from a test CD, wherein you play a monophonic OUT-OF-PHASE signal and position your two speakers until the sound appears to be coming from everywhere, or, ideally, from another dimension. This takes care of surround effects on movies. I do have trouble keeping the phantom center signal exactly centered (and I sit directly in between the speakers), but overall, I enjoy what I hear.
After a lot of experimenting, which I never really stop doing, I decided to try that REL technique of hooking the subwoofer up to my main speakers (which go down to about 40hz) and set the sub's crossover to match. Even though the sub is in the corner, several feet away from the main speakers, it blends in seamlessly. I am not saying that this is because of that technique, mind you. I think the low crossover is mostly responsible for that. However, REL's (and similarly, Vandersteen's) claim is this particular technique allows the sub to become sonically symbiotic with the main amp/speaker combo.
Otherwise, I will say that timing is very important. A roomful of speakers arrive at your ears at all different times and can muddy things up quite a bit. It seems great for a while, but eventually it becomes apparent that things could be improved. Same goes for speaker and sub timing. That's why, in some cases, you may be better off without all the muss and fuss and do the best you can with two speakers.