Okay so here's one big problem with the algorithm. It calculates your route first, and THEN tries to add Superchargers.
As a result, the same algorithm that often has you do a round trip of 50 miles in the
opposite direction of where you are going, also completely ignores Superchargers that are well within your range. And on a better route to your destination.
I've attached a screen shot from my recent trip. From Albany I can trivially drive to Utica, and from there drive directly home nonstop. Or I can go to Syracuse and up the Interstate. Instead, I get a route through the Cornwall Supercharger... which I
can't even reach. Nutty result.
Another nutty result is that I'll tell it to drive to a specific Supercharger
that I can reach on one charge, and it will still try to backtrack me to a Supercharger in the opposite direction. Now sure, the estimated battery level at my destination was 20%, but that was an ample safety margin - and it was completely accurate by the way.
Another oddity is that my iPhone Google Maps application gives me the sensible routes that I actually want to drive
as the default, yet the Google-based car navigation gives me stupid routes that are much longer and slower. I'm guessing only the address lookup is Google Maps, and the route selection is the built-in navigation system (Navigon or something).
So what we really need is a two-stage process. Either let the user drop some waypoint pins (best), or provide alternate routes to select from. Actually both, a la Google Maps, would be best. Only then, once you've selected a route, would the Supercharger search process engage.
Of course an even better solution would be to present several Supercharger-based routes first, and then let the user pick one or start dropping pins.
- - - Updated - - -
A major bug with the current software is its tendency to lock up. If you park the car for any reason (pick up a drink, stop to Supercharge), when you arrive back the system is showing a nutty result and doing an infinitely long recalculation.
As a recent example, I returned to the car after stopping for five minutes for some iced tea, and the navigation system is saying I'll arrive with -1% charge, and it's recalculating forever. Cancel navigation and refresh the address, and the route reappears and it correctly calculates a 21% reserve.
Another bug is the tendency for voice commands to mysteriously disappear. On three occasions during my trip I got to a decision point, and there were no instructions. In two cases I realized something was wrong and peered at the screen just in time to make the right choice. In one case I had already gone through the intersection before I realized maybe I'd gone the wrong way, but it turned out I was supposed to go that way after all.
On that topic, how about a mute on/off button right at the top interface level? Generally I only turn on voice instructions if I'm going through a complex series of turns.
If they could fix the bugs and routing issues this feature would really be very useful... as it stands it only works sometimes.
The energy app Trip screen is great... but is useless if the navigation chooses a different route that is way longer. Which happened three times during my trip. Fortunately Google Maps on my iPhone gave me the correct directions, but I didn't have a trip energy monitoring screen until the built-in Navigation clued into which way I was driving.