maybe rich will have his own views, but for what it’s worth I’d say the rex has been a good choice. Ive had a 2017 rex for 4 years, total mileage 24,000. No trouble at all, and the psychological benefit of the rex is a help. But in reality I’ve hardly used the rex which maintains itself for 10 minutes every 8 weeks. So perhaps not such a good idea to lug the extra weight and complexity the rex involves. The i3 is generally a marvellous thing, but you can start worrying if you read too many of the horror stories available!