Just thought I'd add my experience with James Galway,for what it's worth. Mine grew into a giant,but I found it frustrating beyond words; it's habit was like that of a huge Hybrid Tea,with all the flowers way up where I couldn't see them. The canes were, indeed, so thick and rigid that training them was basically unsuccessful;nor did it flower with great enthusiasm.Often I was tempted to sp this rose,thinking that it would be adapted only to grow as a climber or on a wall- that is, a flat, rigid surface. I held off, because the foliage is so nice and deep green, so healthy, and the plant is thornless and endearingly vigorous,constantly sending up new basals. So finally last autumn I decided to just cut it way back,thinking that perhaps it was one of those roses that just got "too big for it's britches",i.e.,put too much energy into just growing and being huge, so that there just wasn't enough left for flowering. I think I took out all the oldest canes, cut it down to be about chest high (before it towered way over my head). I was delighted to see that this spring, it not only bloomed much better,but also sent out much thinner, more flexible canes. So I guess my opinion is that it wouldn't be my number one choice for an arch,though it might work. If I had a wall for it that would be my first choice.The flowers can be very beautiful indeed, health is perfect as is vigour.