I too have never shot a Smith barrel so the following is from viewing a rifle with a twist barrel and from others/article.
The barrel I have helped work on shot well but not bughole BR well (but that could be related to a ton of other variables). It was quite consistent over a variety of loads.
This seems to agree with other shooters, a RIFLESHOOTER article, and speaking to Ron himself. Seems to be a thought that these barrels are more forgiving and stable even when they get very hot. That consistency helps scores over long strings of fire like F class.
Of course, there are no shortage of top barrel makers using a conventional twist that have similar traits.
I have heard that some CAST BR shooters are using the gain twist with good results but that could just be because the barrels are well made. I have a Douglas that shoots well and has conventional twist.
Nothing definitive. Give them a try, maybe it will work for you. At worse, you will have a quality barrel made by a Canadian.
Jerry