Agreed, I think the mk4 is my immediate mental image of a Jetta. They did a really good job keeping some of the early boxy aesthetics but dosing some more refined fluid lines in.
I think it’s a really interesting styling exercise to take a model that has been around for a long time and refreshing them to today’s taste “au goût du jour”. I’d be curious what’s the impact of keeping models around over multiple generations vs starting fresh with respect to recognition. It seems like different models have had a varying level of success at keeping models through multiple redesigns. Say the Honda Civic which has had roughly 2 major changes to the silhouette or the Porche 911 which got shunned for switching the headlights on the 1998 model. 
Of course two very different cars bought for two very different reasons.