for me the mark 4 (owned 2 years) was such a pleasure to drive - so smooth, so reliable and driving it was second nature with the feather light steering.
The 430 on the other hand i havent been able to get used to - the tire grumble for me is very uncomfortable, the steering heavier - it just doesnt feel like a lexus - gizmos like fridge, rear massaging seats, blind never got used - its not ugly but it doesnt have the sleek looks of the 400.
I have just had to replace the lower balls joints (ok maybe wear and tear) and just yesterday one of the front parking sensors has gone - so overall not a very positive experience
Im hoping ill be back in 400 next week and hopefully i can start enjoying my motoring again - this 430 has given me sleepless nights ever since i had it