There's 1 mm less stack heigth in the forefoot of Gel Lyte33 3 compared to Kinvara 4 but the foam is softer, and for me, it feels more cushioned. I can do the long run in Lyte without feeling beaten up in the end, but the Kinvara feels less forgiving. Maybe it has something to to with the flexibility as well, since Kinvara is torsionally much more rigid and results in a harder "slap" when landing midfoot.
Oh yeah, the drop was 6 not 4 mm, remembered that wrong. Can't tell the difference though with the soft heel.
Anyway Pure Flow should meet your needs, since it's both higher and softer. Cortana even more so, but it feel almost bulky - a bit too much if you wan't some ground feel and responsiveness.