Only had first hand experience with the L2500, but I would pick it any day of the week and twice on Sundays over any J bass.
Why? Well, the purely personal answer is that I despise J basses. MFD pickups sound amazing. If you *really* want a single coil sound from the L2500, you can mod it to provide that with inner or outer coils by changing one selector switch. The G&L bridge is fabulous, apart from the saddle lock feature, it has lovely rounded edges which make it a joy for palm muting at the bridge - no sticky out bits anywhere.
I love Sire basses (I've owned two - had a D5, still have a Z7), it'll be a fine bass, but the V is a J bass and so as far as I'm concerned, it can get in the bin.