A good GPS 3597lmt but not at the top

I am a taxi driver in Paris. I chose this garmin gps after having problems with my tomtom 1005. At presentation, the garmin is beautiful, easy to install, and the screen is very responsive.
Functionally, garmin 3597 lmt did not much progress: proposed street names as soon as the words is clear enough against the combo tomtom 1005 as input to measure well-marked highway exits with an actual photo panels, and often realistic enough routes near my habits, traffic info siganlant the work area, view names next crossing.
Among the flaws that I found:
- Impossible to define a default city is always containt typing city Paris this fault is identical to all gps general public,
- Impossible to change a route already completed forcing repeat entry from the beginning,
- The way that announces street names is sometimes jerky see inaudible in the final words
- The awkward silence or disrupting the GPS programming, ie if you are on an axis of 4 or 5 KM, if you program the GPS en route, the GPS traces the line of the route and gps says nothing while others pronounce gps eg follow the main road or continue straight
- The disturbing silence of gps on one-way streets with a bus corridor against the grain: taxi as I am, I have the right to take these corridor against the grain and the garmin 3597 does not move then to Other gps immediately propose to turn around.
- A frequent delay between the track and my position often when the gps announced to right turn for example, it turns out that I have already turned and passed the intersection.

what I like: very responsive touchscreen smarphone like a very easy setting and programming, photos of motorway exits, traffic info
I do not like: Can not go back to a previous route to change the awkward silence or disrupting the gps after programming, the disturbing silence of gps on one-way streets with a bus lane in against-sense, the difference between my position and voice instruction.

I still recommend this gps