I completely agree with you about the lack of a "wow" factor with this headphone. I felt the exact same way the first time I heard the LCD-2.
When I first heard the K701, my first thought was "Wow! The soundstage is so huge, and the treble is so detailed!"
When I first heard the HD650, my first thought was "Wow! the sound is so warm and lush!"
When i first heard the Pro 900, my first thought was "Wow! The bass literally shakes my brain loose!"
But with all of those headphones, the more I listen, the more I realized that the strengths were at the expense of some increasingly nagging weaknesses. The K701 was too dry and lacked the body to perform well with most genres. The HD650 seemed lazy and washed over the finer details. The Pro 900's recessed midrange buried any vocals beneath the bass and treble frequencies.
I demo'd the LCD's for about an hour at a local hi-fi store. When I first put them on, I was disappointed because for 1K they'd better provide a much bigger "WOW" factor than those mid-tiered phones. Nothing really jumped out. But the more I listened, the more they charmed their way into my soul. They presented the music in such a smooth and natural way, with no glaring weaknesses in its presentation. These were headphones that didn't impose their character into the music, but melted out of the way to let you enjoy your music.
I feel a well-tuned T50RP is the same way. As you've found, the hardest part (in my experience) is reconciling the lower midrange bloom with the bass presentation. It seems the more you improve one area, the more you displace from the performance of the other. I'm not even sure I've extracted the most I can, but I've settled on a happy medium between the two (with a somewhat similar setup as yours).
Yes, perhaps I just need to give them more time. Of course, I won't stop tweaking them!