Sorry Boycey, only just noticed your message.
My reason for going diesel was, more economical, cheaper fuel, more robust engine and I hoped servicing costs would be cheaper too, not too sure about that. Also diesel is far less flammable than petrol.
Another reason was theft, I thought it would be less attractive to thieves.
The downside is that the engine takes up deck space, there is a bit more to service with the drive leg.
Mine, a 6.5 metre, only had two seats and one at the front of the console.
Although I felt it could have been reconfigured to create two more seats.