My comments below are based on the assumption that you have the guitar and are planning to better it. If it's a generic question about features and all, I'll leave that to the product designers at the respective companies.
What is the top wood material? Is it maple?? Maple veneer/phototop/cap? The woods used define the tonal characteristics of the guitar, and modifications to pickups/hardware should be done keeping in mind.
Having said that, Active pickups disregard most everything.
What material is the nut? If its plastic, replacing it with a bone/graphtec would lend a lot of tuning stability. What condition is the fretboard in? Oiling it might help. Open the control cavity and check out the hardware. I'm pretty sure you'll have ceramic capacitors which can be replaced by PIOs for a much better tone.
What kind of pickups are there? PAF or high output? Do you have an idea of the pickup resistances? Are the pickups 4 conductor? If yes, you could wire them for split coil.
Is the truss rod adjusted and the guitar intonated properly?
Is the set neck a short tennon or a long tennon. Although you can hardly do anything about it, it helps to know. You could upgrade to a wraparound tailpiece for more sustain.
Innumerable number of small tweaks/upgrades to a guitar can be done, all of which help in improving some or all of the features/characteristics of the guitar. It depends on your interests, availability of time and budget to undertake these.
My gear, currently up for sale
Washburn X-16 anarchy - SOLD!!
duncan pickups - I wonder why Im selling these.