I find I like the Lucifer more than the Sath. The way it always popped in without warning, dominated the scene and you always knew it was THE Lucifer, not A_Random_Sathanas_08, made it a more powerful presence to me than the Sath, despite being smaller, wielding less firepower and looking less cool.
Btw, I don't have FS1 installed to check, but I think they said that the Lucifer's shields were so strong that nothing in the GTA or PVN's current arsenal could penetrate. Doesn't say if it's merely so strong that it just absorbs the attacks or if it somehow bounces off or something. Considering that the arsenal of the GTA included the Harbinger, which is still a fairly powerful bomb, and still made no effect (invulnerabilty tag is cheap) it might be a completely new technology in the shield, rather than just a giant version of fighter shields.