Hi, I have an L2000 fretless. I epoxied the board and got the single coil mod done. Contrary to almost everyone else on this board, I wasn't a fan of the single coil mod. In my opinion, it really thins the sound out. I can see it being useful for some people in some situations, but it isn't for me. I found that I could get a pretty good Jaco tone from the bridge pickup, series, passive, DR Low Riders. But like I said, that's me.
Plus, I like big bottom. I am willing to sacrifice some clarity for making the bass sound like a bottom dwelling creature. Not everyone is into that.
The epoxy, however, is another story. My experience is that it really does increase the mwhaaa factor. It is a mod that will have an impact, no doubt about it. It is also something that is about impossible to change once it is done, so be sure that this is what you want. The feel, the tone, everything changes about the instrument once you do this, but if you are considering it, you probably know all this already.
Personally, I would do it again. But that's me and all that other stuff.
For those wondering, I think it is quite possible to get close to the Jaco thing with an epoxied L2000. Not 100%, but in the neighborhood. Plus, an epoxied L2000 will allow you to do a whole bunch of stuff that Jaco's bass couldn't, in my opinion. Not to knock the master or his tone in any way, but I am really happy with my fretless. The L2000's versatility is even more useful in the fretless package, in my opinion, because a fretless bass is really called upon to do a whole bunch of stuff. And in the hands of someone who knows how to play the instrument and the tonal variations it provides, I think the fretless L2000 can really deliver whatever you need.
John