We have installed some 575 electric drives on boats since the early 1990's; which is arguably the most experience of any manufacturer.
Here is the skinny:
1) for boats under 4,000 lbs; pure electric is a very compelling proposition. If it was my boat, I'd always use electric in anything under 4,000 lbs.
2) for boats over 7,000 lbs; one has to be very clear about one's requirments. A typical range is going to be 90 minutes at hull speed and 3 hours at 1/2 hull speed. This ranges can be significantly extended motor-sailing. These ranges and also be significantly decreased in heavy weather.
3) hybrid systems, at this stage, work fine but tend to be pricey and the user should have a reasonable technical understanding of the system.