New to Lexus here and a neophile. I've been giving the built in sat nav on my 2016 RC a work out. It's fine. Not great, but usable. It's gotten me to where I needed to go, had traffic updates and whatnot. It's got a nice 3D view, which is what I prefer.
The maps are old at 2015 but just today ordered a map update, as it didn't have the Huntingdon bypass for instance, which messed up some routing suggestions. A few places, didn't quite recommend the correct lanes either, specifically coming from the M6 to join the M1, says to "go slightly right", when the lanes are on the left and then go overhead to curve right.
Not being able to input the full post codes is unfortunate. Also wish I could change the default destination input mode to be post code.
It's no Google maps, but in the end it got me where I needed to be in time, which is what matters.
I haven't had old school maps in my car for 10+ years. If the built in satnav can't cope, I'll use my mobile phone. Or perhaps even look out the window and pay attention to signs. But that being said I will look at an online map prior to my journeys to understand the rough route.