They tend to be about 8oz so are usually lighter which means less effort and faster. I do like the Addis £2.99 monofilament brush (rt in pic), it splays on the glass and wears very well. But some may not like that. I find that I can cut into the corners and edges and its great for georgian panes. But if you wanted a flocked brush and do frames the Tesco "Melody" 9oz is probably nearer to a vikan.
Fit your jets over or through. Generally they suit domestic work very well, but I use mine on the commercial as well.
If you do try one, use it for at least a week, it may just grow on you.