I hope someone can answer these questions:
1. Is the 740b any faster than a 740?
2. Is the 740 battery replaceable? And available? (This user is not afraid of soldering irons, etc.)
Why do I ask? Because an ancient 740 is my all-time favorite GPS navigation device. I use it every time I fly--several times every week. And it's semi-permanently installed in the instrument panel, right where it ought to be--and also drives the autopilot.
On the other hand, it needs a new battery and its processor is rather slow, especially compared to the iPad Mini 6 that I use as a supplemental backup.
So I'm thinking of buying a 740b, rather than enduring the downtime from sending the 740 to AP for repair.