Like Matt said, the bass of the LCDs has a bit more weight to the bass, and it is a bit cleaner too. That is the thing I noticed about orthos is that they do a good job of putting focus on all the parts of the sound. Everything is in very clear focus with excellent detail and texture. But I feel that for me, there wasn't as coherent or natural a whole to the picture as something like the HD800 or even the HD650 in some respects.
The HD800 does not have the warmth or boosted mid bass of the HD650, it is very balanced all the way through. That said, the HD800 has very articulate bass that can punch quite nicely when called for (this is where giving them enough voltage comes in). Where the HD800 excels for me is creating space. Better than any other headphone I have spent a lot of head time with, the HD800 allows me to forget I am wearing headphones and places me in the performance, especially with well-recorded classical and acoustic. It comes closest to a live performance for me (my goal). I think with that ability, they would be phenomenal gaming headphones (albeit quite expensive one). You aren't going to be overwhelmed by huge farting bass during explosions, but you will have quite an immersive experience I would imagine (I don't game on my computer anymore).
Like I mentioned before, I think the Sennheiser siblings are excellent complements to each other. One allows me to be in the recording and the performance, the other lets me lose myself in the music.
The bass is cleaner and more articulate on the lcd series. A little better textured. It's a very good hp, just too heavy for me.