I feel like the suit w/o tie gets a bad rap because people tend to transition to the tieless look but using the same suits they've always worn. Seeing a guy in a slightly oversized charcoal suit with pleats and cuffs, an OCBD shirt and an undershirt peaking through the collar and associating that image with "suit without tie" is enough to turn anyone off to the look. And, similarly, the suits I'd wear without a tie aren't particularly appropriate for a business meeting in a conservative atmosphere.
The fit, for me personally, will be different too. My go-to suits are RLBL and I'll buy a different size and tailor them differently if I plan to wear them with vs. without a tie. With a tie I'll buy a 42L and let out the trousers so they hang nicely when worn with braces. For without a tie, I'll buy a 42R and not let out the trousers so they stay up on their own w/o braces and appear more fitted around the seat. Might also have the trousers tapered a bit. I'll also go with different fabrics; I wouldn't do a chalk stripe or windowpane without a tie, but might do a light glen plaid or solid solid steel blue without a tie.
If I weren't consistently buying the same cut of suit, I'd also choose softer shoulders and a slightly higher button stance for non-tie suits.
This is an example of something I'd wear w/o a tie:
And here's one I'd only wear with a tie:
The shirts I'd wear with each would be different too. As has been suggested, small patterns are probably better than bangle stripes or solid broadcloths. Smaller collars, also, look a bit better without a tie. And please, no contrast collars or undershirts poking out.