I don't know much about Ellicott City schools, other than they uniformly have good reputations. I grew up in southern Howard County, which has some lower income areas. My nephew still lives in the general area (nicer neighborhood), and both he and I have done Hammond Elementary, Hammond Middle, and Atholton High (Laurel address).
Diverse, nice kids, smaller classes than what we've got here in Montgomery County. About 25 kids on average.
I think Howard is a really good school system. It's small enough that it has some flexibility to target and solve problems. Montgomery County seems so huge, and it takes forever for anything to get changed or improved.
Howard County does redistrict fairly often, though, so you could buy for a certain pyramid and find out somewhere during the K-12 years that it changes.
You didn't ask about Baltimore County, but I have friends in the Catonsville area and they've loved their school experience, too. At least up through elementary.