You appear to have asked the same question here as in the 'Pickups' forum, so I will post the same reply here...
Over the last few days I have played 3 EBMM (2x 2-band and 1x 3-band), an SBMM Ray34 3-band (my own) and a SubRay. If I were to be brutally honest, they all capture the essence of the Stingray sound and the main differences were in materials, hardware quality and playability rather than overall sound - all three are capable of 'the sound', but the way they respond to the player, and therefore what the player needs to do to achieve 'the sound', is different.
IMO, the pickups on the SUB are fundamentally good and a poor setup can make a 'real' ray (or any instrument for that matter) sound terrible. On one of the 2-band EBMMs I tried, the pickup height on the bass side was too high by about 1mm and it was producing horrible wolf tones and a weird 'tremolo' effect above the 12th fret. A few seconds with a screwdriver fixed this and changed the whole character and tonal balance of the bass across the whole range.
FWIW, I would try getting the most out of what you have before shelling out on a new pickup. Even then, if the instrument is not very responsive or is badly set up, no new pickup will compensate for that.