I don't know all that much about electric razors, but we have sensitive skin in our family too and I can relate to the 'horrible time shaving' episodes. Is he putting anything else on his skin, before or after he uses the razor? Maybe he's pressing too hard? We find they never gave a shave as close as a razor, regardless of what the ads claim, so pressing harder just irritates the skin.
For my husband, he doesn't shave often, but when he does, he found that one of those three blade razors work well, and he only uses one of two kinds of soap lathered up with a shaving brush. I'm quite proud to say that I make one of those soaps and it's made with colloidal oatmeal, so the proteins make the razor slip really well, and there is no fragrance added because chemicals used to make fragrances can be very very irritating for people like us. I didn't originally formulate the soap to be a shaving soap, but we discovered by accident that it works even better than the stuff he was buying at The Body Shop.
Something I've been using on my skin after shaving my legs or giving myself a facial is plain old rice bran oil, straight from the bottle I buy at the grocery store. It had lots of vitamin E in it and it's a very light, non-clogging oil. They've been using like that in Asia for generations. Maybe this can help your husband's skin too. It's a nice light moisturiser with no odour and I've been recommending it to the guys who buy my olive oil-colloidal oatmeal shaving soap.
Good luck and let me know how he gets on.
C.