The short answer is REx. Along with my 'reasoning' I thought I'd also try explain why I think the REx works so well so I'm afraid it's a bit of a long post....
When I was making this decision last summer I originally wanted the BEV. It's 120kg lighter, £3k cheaper and technically the purer solution with the feel good factor of never having to visit a petrol pump. However, my driving regularly takes me well outside of BEV range so seeing as this was my first EV I started reading the LEAF forum to see how people coped with long distance trips. It wasn't a pretty sight and I knew for sure that I didn't want the hassle of public charging. I know there are a lot of BEV owners who do big mileage but I don't enjoy that kind of challenge. I don't even want to wait 30 mins in a service station car park, certainly not when with family or friends. Sorry, that's just me, lazy I know
I wasn't keen on the inefficiencies of buying a 2nd ICE car for the longer journeys so that option was ruled out. The decision actually came down to ICE or REx but the more I thought about it the more I really wanted an EV so REx it was.
Now that I'm 3 months in I thought I'd explain a few examples of how I've come to appreciate the REx
1. My daily commute leaves me returning to my house with only 20 miles or so of range remaining. I charge it overnight on the cheap tariff but that means the car sits all evening with a low SoC before charging starts at midnight so if anything unexpected comes up and I need to drive somewhere the REx allows me to do this. I'm not sure I'd be comfortable if I owned the BEV in this situation, I'd probably be wanting to plug it in as soon as I got in from work which would mean more expensive charging (15p per kWh rather than 4p).
2. One Saturday I went shopping where the car park had 32A chargers but I'd never been before so didn't know if I'd have the right card. I deliberately didn't bother charging the night before so I arrived with 8 miles range left, my card worked and I departed later with a fully charged battery. That's not something I'd have risked doing with the BEV. A minor perk but a nice one
3. My car has twice failed to charge overnight. I'm a contractor who gets paid by the hour so the REx saved me ££ here by allowing me to just get in and drive to work rather than having to wait 2 hours for the car to charge.
4. Long distance motorway trips have seen the car giving approximately 160 miles in total range (battery + REx) and each refuel gives another 90 miles which works out about 45 mpg when running the REx. My 200 mile trip to my parents just needs 1 stop for 5 mins to refuel and the total journey time is only a few more minutes than my previous ICE car. A BEV would be 2 stops and at least an hour extra.
Oh, and one last thing, maintenance : I've read comments suggesting increased maintenance and servicing costs for the REx. Actually, it's not a big deal and that's because of how little the REx is used. Less than 10% of my mileage is done with the REx so that's going to be around 1250 miles a year i.e. much less than an ICE car that typically needs oil/filters changed every 12 months. The first service on my i3 is not for 2 years and I bought a 5 year service plan for £375 so you can see that REx maintenance costs aren't really significant. For reference, the i3 BEV service plan is £325 so the REx effectively works out costing an extra £10 per year.
I know there will be BEV owners reading all that and thinking 'meh' but, like I've said before, the REx was needed to convince me to buy an EV. I'll probably purchase a BEV in future when ranges increase but in the meantime the REx has made it all very easy allowing hassle free long journeys and a peace of mind knowing that if anything unexpected crops up I can just get in and drive 'like a normal car'.