One thing to remember on the electronic muffs-- they are just regular muffs with speakers inside and microphones on the outside. So if you get the low profile or thinner ones, you're getting less protection. There's no question that they are lighter, and maybe more comfortable, but don't think you're getting the same level of protection.
Also, I've used some Caldwells, and they do seem to work on a basic level. But when you spend more, you get a better and faster processor; when a gunshot causes the sound to be blocked out, you will get the sound returning more quickly with the better muffs. If you're on a firing line with constant shooting, it may be a moot point anyway, but in my experience, in many situations there is a noticeable difference.
Also, I've used some Caldwells, and they do seem to work on a basic level. But when you spend more, you get a better and faster processor; when a gunshot causes the sound to be blocked out, you will get the sound returning more quickly with the better muffs. If you're on a firing line with constant shooting, it may be a moot point anyway, but in my experience, in many situations there is a noticeable difference.