FWIW, and bear in mind that this is one person with two pairs of speakers which - by the standards of some here - are probably classed as "not good", I would agree that hard-dome tweeters are 'harder-sounding' than soft-dome ones, but I would not go as far as saying that they are harsh or fatiguing. Over my 45+ years in the hobby I have listened to many speakers using both technologies, and the general character of both types of transducers remains fairly consistent in my memory.
There are good engineering reasons for using both hard- and soft-domes, but they do come with trade-offs in how they present music; the designer has to make a choice based on multiple factors, of which timbre is only one.
Ultimately, as in many cases, your ears are the only reliable instrument of what you are going to like.
(My speakers: Sonus Faber Electa Amator; Focal Solo 6 Be)