My thoughts basically. I probably wouldn't want to bare my braces if they are clipons, but, I think it's overly fussy to condemn clipon braces entirely even if sure button ones are preferable. If you have trousers with no buttons and they won't be seen then who cares, especially if you're wearing, say, db jackets.
Clip ons are less dependable, not to mention harsh on the cloth. Don't want a loose one banging around because it came off.
Button braces has more flexibility where it matters. And they are more reliable. These are technically far better.
Trousers that are properly made for braces are cut different than for belts. When ordering be sure the tailor knows if for belts or braces.