I installed one (a DJ Retro) this week into my Lakland DJ. Installation isn't too diffucult. The pickups can be connected using screw terminals. The ground wires need to be soldered though. Screw terminals aside, it is a good idea to tin the wires from the pickups before screwing them in. So being able to solder propely is a must imo, having a wirestripper, solder and iron too.
Fitting it all in the cavity is fiddly, you will manage with a bit of patience though. Note that you may have to do some minor woodwork. Mine would not fit as is. The active/passive switch needed some room to fit. I removed a bit of the side wall of the cavity to make it fit.
Soundwise a big step forward from passive. The mid sweep is great to have. The bright switch is indeed bright, too much for me, ymmv. Being able to switch to passive is a great addition should you encounter the dreaded flat battery. I'm happy with mine. Good luck!