I love cheese and there is nothing wrong with Cabot. That said, if you can't taste the difference, then buy what you think is best for your family. I personally can taste the difference between the brands and types. You might just not be a cheese person.

For cheddar, we like Seaside cheddar from Whole Foods. To me it tastes very different to the brands you mention.

For cheddar I think the English stuff is best. It is named after a place in England, after all.

My goodness NO! Every cheese is different, but as PP said, you need to taste them in the right context. The sandwich is masking a lot of the cheese flavor, and what matters more here is probably texture (not too brittle), instead of fine differences in flavor.

I'm French. When I vacation in the Alps, the fromageries offer winter and summer versions of the same cheese, and you can taste the difference, because cow milk will taste different when cows eat winter hay and when they eat alpine summer grass. It's amazing. Some cheese also don't travel well. The exact same cheese won't taste as good when you buy it in a Parisian fromagerie, after it's traveled a few hundred kilometers and stayed out for a days in a different setting, than when you buy it at the farm where it's been made, in similar conditions of humidity and temperature.

Getting off cheesebox now.

Depending what you are adding to your sandwich, it may be more the issue that your sandwich is not the best vehicle to highlight and appreciate the cheese. We love just snacking in cheddar (by itself).

For a go-to sandwich cheese for the family, we have been buying different "good" cheddar at the farmers market. Imported, domestic, modest priced to expensive, and nobody in the family really notices or detects the differences. Cabot and Kerrygold's 12-18 month white cheddar for $6 from a grocery store seems just as nice as the "good" stuff. I want to like and appreciate the "good" cheese and I like giving the cheesemonger business, but it feels like a rip-off. Or maybe we need to venture off of cheddar?