Which is better for standing all day?

The 990v3. Its polyurethane and EVA midsole gives more support and resists compression longer than the 997H's EVA-only sole.

The 990v3. The PU midsole and Made in USA build hold up better over years of wear; the 997H's EVA midsole flattens sooner.

Is the 990v3 worth stepping up to?

Yes if you want a wide fit, more support and a longer-lasting shoe. The 997H is the lighter, simpler choice for casual wear.

The 997H V1, at about 11 oz. The 990v3 is heavier because of its layered upper and denser midsole.

Do they fit the same?

Not exactly. The 990v3 comes in wide widths and runs roomier; the 997H V1 is standard width, so size up if you have a broad foot.

Which has more owner feedback?

The 997H V1, with 146 ratings against 13 for the 990v3. Both score well, but the 997H sample is larger.

New Balance 990v3 vs New Balance 997H V1

Buy the 990v3 if you want the flagship Made in USA build: suede and mesh upper, polyurethane and EVA midsole, and a wider fit. Buy the 997H V1 if you want a lighter, simpler everyday sneaker with a broader size run and far more owner feedback. The 990v3 is the better-made shoe and holds up longer; the 997H is the easier one to wear daily and replace.

Choose the 990v3 if you want the Made in USA 990 line, a supportive PU and EVA midsole, and a wide width option.
Choose the 997H V1 if you want a light suede-and-mesh sneaker for everyday wear and a straightforward lace-up fit.

Prices

New Balance 990v3: $69.90 at Walmart (checked today)
New Balance 997H V1: $55.52 at Amazon (checked today)
Difference: the New Balance 997H V1 is $14.38 cheaper than the New Balance 990v3 today