No, nothing especially wrong with the latest generation of B737 aircraft, they do the job to nearly everyones satisfaction, except...
if you have flown one specific type before, and relied on its automatic approach/land mode of operation extensively, and then come to realise that, on re-qualification on this older type, after having flown the B737-800 for some years, that the later Boeing rehashed design simply cannot measure up to older 'technology'.
That 'older' type of course...is the Lockheed TriStar.
Or, so I'm told anyway, by those whom have flown both types extensively.