I traded my LS 430 for an LS 460 this last month. The 460 is comparable in interior size and leg room although the trunk is a tad smaller. The car rides well and is a bit more noisy than the 430. The electronics (radio, DVD, GPS) are great but complicated and require a bit of concentration to use.
Roomy interior. Clear display and controls. Plenty of power.
Enlarge trunk. Center console too wide and restricts arms.