Ok, so the TI flats feel much more familiar to me, because I already have them on two other basses. Not dramatically different to the Monels, but definitely more clarity, less wooliness and more tone options, so I'm going in the right direction. However, I'm thinking that the inevitable outcome will be that I'll need to try rounds too, just to see what I get.
Maybe, which has just occurred to me, I could be trying to default tonally to my normal fretted tone? Does that make sense? In other words I need to understand that the tone from a fretless is a different thing and I need to roll with that and enjoy the difference.
Decisions decisions....