After years of dealing with directional noise in my Starfire with the ancient Series pickups in there, I finally got a new set from the mothership. The noise is less, although still there, so it looks like I'm going to have to look into better shielding and perhaps an electronics upgrade.
What is interesting to me is how the tone has changed.
What I've gained:
Overall smoothness and consistency of tone. The new pickups bring a very consistent tone across the whole range of the bass, so that different registers sound much more like they all come from the same bass.
Fuller low mids. The bass sounds more present in the low mids and more solid. I think this contributes to the consistency of tone as the fundamental and first harmonic live in this range.
What I've lost:
The original pickups had kind of an airiness to them in the high end and similar extension in the lows. While the new pickups aren't lacking in low end (or the high end, for that matter) and in some ways seem more solid, the old ones had a more nuanced character in the low end. I don't know whether this is due to the number of winds of wire (the old ones had very low resistance, in the 800-900 ohm range) or to the change in shape of the magnets from trapezoid to rectangular.
What does this mean for me? Option anxiety! They both sound really good. Right now I'm really liking the consistency of tone and the more solid low mids of the new ones. If I were to draw a comparison, it's like moving from 1972 era Phil Lesh to mid 70s. A slightly more solid body sound, perhaps. Plus, black looks pretty cool.
I'll try to get some samples put together and post them.