I am only speaking from my personal experience from driving, being a passenger, and talking to other people at meets in all different types of cars with brand new and old bc's.
I did a few months research on what people thought of their suspension and I personally didn't find them good enough for the price. Some people weren't happy and others loved them and as you said, were fine and worked flawlessly. I couldn't find a bad word about mca, even with their higher spring rates it seemed the valving was superior. I didn't want to take a gamble on $1300 for the bc's.
The cars i drove and was a passenger in the bc's were rock hard and bouncy at the same time. This showed me the valving was not up to the task. Or a case of being height set from the base and hitting bumpstop, but still the rebound was not up to the task even after tuning. Most of the cars i was in had the standard spring rates the bc's came with (skylines are 8-6?)
I am glad i spent the extra $200 for the blues. I am also glad your bc's work great.