That was a good road trip PanE.

I am not an iPhone enthusiast so I will not pass comment on that aspect.
However -
I wouldn't, personally, spend 100 of any currency on a smart phone app simply to trial it when there are so many free ones out there.
In fact my smart phone cost less than that in GB pounds.
And, you bought maps when OSM is out there on many apps for free.

Naturally, nor would I spend 800 tokens on a GPS!
So, we are definitely in two different economies.

I don't know anything about the sygic display but many of the competitor apps have displays that can be tweaked i.e. pre-set by the owner/user to display just about whatever is required, or display just the map. I imagine that only the most expensive GPS have that same feature.
One of them that I tried out over a year ago has a pitch, roll and yaw option that might appeal to you e.g. could be useful in a microlight.

I don't arrive at your lessons learnt therefore, primarily for the reason that you trialled just one of the vast range of apps that are on the market (and an expensive one at that!); the thinking about the pros and cons are well explored in earlier posts, including the aspect of urban Vs remote area use of navigation aids.

Incidentally, but of relevance, I would have liked to know how your trial coped with aural navigation - in the sense that I much prefer listening to a navigational aid rather than developing "screen fixation".

I look forward to reading about your future trials!

__________________
Dave