My KD recommended slightly rounded (which i also have now) because the square ones are harder to clean in the corners. i like what I have now (pre-renovation) and am happy to get another one just like it when I do the renovation.

We have a Delta workstation sink with ever so slightly rounded corners and much prefer the ease of cleaning to our daughters sink with sharply squared corners. They’re difficult to clean well. I don’t find our rounded corners to impede cleaning larger items at all.

The most important thing is the actual size of the sink. Squared or rounded won't change your life much! My main sink is 30" L x 18" D x 10" H. A lot of sinks are only 16" deep, which I think makes a huge difference in how big the sink feels and having room to maneuver larger items. If your sink has a ledge of some type, that will also reduce the depth, so look at all the specs very carefully.

I can confirm the square corners are hard to clean. The sinks should come with a special tool for that.

'Small radius' corners in a welded sink. Not the welded sinks with 90 degree corners.

And then there are the large swooping corners in budget stamped stainless steel sink.

I prefer the small radius welded sink. A lot of stamped sinks are cheap and look cheap.

Your friend's "square one" may be a sink that has what are called "0-radius corners". The radius refers to the angle of the corners. Sinks come in different radius corners, i.e. there are different degrees of roundness or squareness in kitchen sink corners.

A sink with ”tight radius” or "small radius" corners means about 10-15° corners. That is as opposed to 0° in a ”zero radius” corner. There is also a very rounded corner, also called a "standard radius". The more rounded "standard" sink corners are seen on builder-special style sinks which are lower priced and often lower quality.

I have never heard of cleaning issues with a sink with tight radius corners. The tight radius corner is a nice compromise of still having a modern look without such an extreme corner, while not having the very rounded corners of older-style sinks.

Exactly this ^^^

I had a zero radius once. UGH

If you don't believe us, visit a showrrom that has working sinks. Zero radius sinks will have gunk in them.

I have a single bowl with small/ tight radius corners. It is not difficult to clean the corners. I really like the look of it and would buy one again. Would not want a zero radius sink.

Yes to single bowl / tight radius kitchen sinks! My first SS single bowl kitchen sink was zero radius & yes, they do require more effort to clean the sharp corners. The tight radius has just enough curve in the corners - I know - sounds like a contradiction - but it is still a corner & it does have a tiny curve.