I took the plunge and bought a Hyundai Ioniq plug-in hybrid in September last year and I must say that I am not disappointed. I did a lot of analysis before buying the vehicle looking at life costs of petrol and diesel models, hybrid models and plug-in hybrid models and over a six year period my analysis indicated that the plug-in hybrid was the cheapest solution. However this really depends on the mileage that you do each day. My daily commute is about 35 miles return so I can do it on a full charge and therefore get about 250mpg. We took it to Bordeaux on holiday in the summer and this dropped to 86mpg because we ran on the petrol engine for most of the way. It uses about 7.1units of electricity for a full charge so if you are on Economy 7 it costs about 35p for 35 miles. I must say that these figures are noticeably reduced in the cold weather.
I wasn't brave enough to go totally electric and my experience to date of the charging network verifies that, but maybe Dorset is not typical. I seem to be exceeding the efficiency used in my life cost analysis which makes it even cheaper. Could ramble on even more but in conclusion I would recommend looking at plug-in hybrids because you get the best of both worlds but this is highly dependent on the daily mileage that you do.