All right, now, I need the straight poop here! (Pun intended, of course)

Looking at marine heads, it looks to me like I should replace my current
"pumper" with either an electric SeaEra or an electric Lavac. I don't quite
understand how the Lavac works . . . but they are supposed to be "the most
trouble-free" available.

Any comments? Peggy, help!!!