Hoselock because they are more common, and fan jets as I find they are better for rinsing, though we use both straight and fan and there's not a great deal of difference.
Just bought a 15' pole from cleantech for £30, bought it to go with a backpack from them, all as a backup in one of the vans that doesn't do a great deal of window cleaning, our first impressions of both the backpack and pole are very good.