I really agonized over the decision to trade up from my 2004 TL - I loved the technology, styling, acceleration and fuel economy. The "killer app" on the RL was navigation with real-time traffic. The first time I drove the RL it felt "floaty" to me. Now that I've driven it for a month, it feels serene. Interior amenities are much nicer than the TL - I don't ache anymore after an hour and a half on the road. The sound system ROCKS and technology is nicely integrated. The real-time navi saves some time, though mainly it gives a sense of mastery over the environment. Handling is secure, especially in the curves. Gas mileage is so-so, around 20. I love that there are no options.
NavTraffic, great sound system with XM radio, adaptive cruise control, great seats, amazing value relative to competitors, rarity on the road.
A few more HP, 6-speed tranny, standard iPod link, edgier stying.