I see your dilemma, I had the same with mine. It's ok but I don't love it, and it constantly needs things doing to it. There just isn't anything that I do day to day that I think "that would be better in the defender".
For what it is worth I am 100% selling mine when it has been painted. I'll probably regret it and miss it at some point, but I seem to like the projects more than I like the actual using of them.
It helps that I already have my next project
I would probably sell the series and the defender then keep the D1 for everyday and the jeep for fun stuff