Just got done turning my 2003 ReBop4 into a hot rod! I took out the stock EMG HZ pickups and replaced them with the 35P4 at the neck and the 35CS at the bridge. This is a huge difference in tone and clarity. The 35P4 has that nice reversed-P tone like the configuration of the NS-2 with the traditional split half P pickups. The 35CS has a warm tone that compliments the other pickup.
I used the supplied EMG 25K volume pots and the B157 Pickup Buss, which allowed use of the cables with the connectors for the signal, ground and power. So, there was mininal soldering for the TonePump and output jack connections.
Back to the tone, I do prefer the EMG active pickups (like I have in my Euro5LX - DCs). They really bring out more of the Spector sound, that signature growl and the punch of the ReBop. With the HZs, it did not sound as clear. This is a great upgrade!