Hey Bill: I just got my new bass with LEDs (green). Apart from the aesthetic appeal (They look outrageous with the caramel and black coco bolo), I'm surprised at how nice they are to have. Admittedly, in high light situations, the aluminum dots Alembic puts on as standard are adequate (though a bit skimpy for my taste). But in any other light situation, they definitely increase my feeling of security that I will not reach for a high A and go sharp or flat (as well as helping with other position changes). My teacher, who's made his living playing bass for 32 years, is considering an aftermarket fit for his bass since he played mine (for the same reasons).
I have a cut-off toggle for the LEDs, but no brightness pot. I bought the toggle option because I wasn't sure I'd use them too often. Turns out I was wrong. I rarely turn them off. But I might prefer the ability to dim, brighten or cut off if I had to do it again.
Now - the disclaimers - I am 50 and suffer the same crappy eyesight most 50 year olds have. LEDs are quite expensive, compared to other things you might buy instead. Nonetheless, I'm glad I bit the bullet. I would encourage you to hear from lots of others if that will help you assess what's likely to be worthwhile to you.
For instance, I might ask people things like: Would you trade in gold plated hardware to get (or not to give up) LEDs? Unfortunately, it's hard to compare too many comparably-priced options on their practical benefits.
When you order your guitar, make sure they post progress in Factory to Customer (If that suits you, of course.). I haven't gotten to see a lot of Furthers. What kinds of woods and other options are you thinking of?
Good luck,
Bill, the bass one