I've put the original bridge back on just to see the difference. I actually prefer it - somehow the D and G strings in particular are warmer and fuller, whereas the Albridge is more treble and more even. Whilst this might be more desirable on fretted bass, for fretless I think the original sounds better - there's more 'cross talk' between strings and overall the whole bass feels more alive, less clinical. Trills, for example, are much more pronounced and there's a thicker more midrangey 'mwah' to the notes, despite the bridge not going as low in terms of action as the Albridge.
I really was quite surprised by the difference, it was really clear from the first note. As a result, I might sell the Albridge if anyone in the UK is after one (I'll list it later)
There's something about the shonkiness of the original that I like, too. Whilst the D and Gi intonate very well (more by luck than judgement) the E and A are fairly close up to the 9th, close enough for fretless...
The Osmo oil finish on the fretboard is holding up perfectly, I am pleased to report. Amazing stuff!