I bought a
Tanglewood fretted bass (Warwick copy) some time ago. It was a pretty horrid thing that needed a lot of work to get it to play half decently, including needing six - yes six !, neck shims to have a relatively low action. I decided to de-fret it and make it fretless, in order to get some possible use from it.
The de-fretting went well, taking out minimal chips from the fingerboard, then lots of sanding and filling the fret slots with super glue, which dried a bit oddly and made it look a bit peculiar. however, it did the job and it now plays and sounds really quite good now - even though it still looks pretty 'orrid.
My
ESP LTD fretless is still very nice, but it's a struggle for me to play it as it's right handed and I'm a lefty.

I'm planning on having fretless on one of my upcoming projects, which will be primarily ambient 'electro-guitar'

I'm well behind schedule with that, but it will see the light of day later this year.