I've been doing electro for about 10 months now, my advice would definitely be to use laser for neck and sideburns first, then move to electro to finish lighter colored hair. Expect to undergo some electrolysis for stubborn hairs, though.
Lessons I've learned? 1). Take Tylenol before you go for treatment; 2). Stress will create a horrible shadow that is very difficult to hide, regardless of how smooth you may feel; 3). Related to number 2, surgery counts as "stress" and creates a shadow - for me it's always my upper lip that shows a shadow, no matter how much I shave.
My electrologist is very picky about the treatment that "her" girls get, and one of her biggest concerns is scarring related to laser. She's way WAY overbooked so I am convinced that her concern is honest and not related to her financial interests.
Mia