The update makes the system seemingly operate more quickly and smoothly, it may just be that the animations speeds are quicker.
For me personally I find the latest update an issue because I listen to podcasts on my iPhone and when one finishes the system seems to hang and doesn't let me browse again without having to reset the system.
If Lexus would publish these updates on their website or on the customer portal it would be quick and easy for people to upgrade, having to book an appointment and waste time and petrol to visit your dealer possibly isn't worth it for these minor updates unless you are impacted by a specific bug.
Whether an update will fix an issue seems to be an unknown as Lexus don't issue release notes, not even to their dealers!
You can probably tell I'm not entirely satisfied with the Infotainment system. Poorly implemented software combined with a lack of transparency and poor customer service isn't what I would expect on a £2,000 option. Given that they have such a bad system I would have expected Lexus to implement Apple CarPlay and Android Auto as quickly as possible and just give up, unfortunately they are taking the opposite approach and want to try and make as much money out of their existing investment as possible.