I've just upgraded to a Mk 2 SE-L 3 weeks ago after 4 trouble free years with a Mk 1 SE. I was concerned about the Air-Suspension so for peace of mind eventually bought it from Lexus Cambridge (Very Good service)Even with the crap tyres (Sumo Firenza ST-08 on 235/55 r18's - Very Noisy)we find the ride much more comfortable, but that could also be something to do with the seats!
Also the Mark Levinson Sound System is excellent but I've noted the potential problems that other members have posted. I plan to add a Denison Gateway 100 so that I can connect my i-pod.
Good luck with your choice
MGC