Well, I found it interesting to be able to compare the Mk4 with my Mk3. However, any possible debate as to which to own has resolved itself through two factors:
1) The Mk4 owner decided not sell, and to be quite honest with the money he's put into it I can't blame him at all.
2) My Mk3 passed its MoT today, with apparently just a bit of headlamp alignment required. I was somewhat surprised, I'd given it no preparation whatsoever, and it came as a welcome relief after my wife's 2002 Accord incurred us a rather hefty bill for an MoT and service earlier in the week.
I ended up using the Lexus for everyday duties for much of the week, not ideal weather for a powerful RWD car on icy/greasy country roads but it coped admirably. Understandably I'm rather pleased that I can keep using it and will now put a little bit of effort into getting its various minor issues sorted. A bit of a wash might not go amiss:
Lexus update by Spottedlaurel, on Flickr