It would be great if you could have more than one active sketch window open, so you could flip between two models while still in the sketch window on both models.
Currently you have to cancel out of sketcher (or it forces you to) and switch to the other model and go back into the sketch to interigate. Then cancel again and switch windows and go back into the sketch again. I find myself on complicated features going back and forth numerous times to see what the references are, or write down all the dimensions that I need to copy. It has got better in Creo 3, as if you are lucky it highlights the missing references (edges in a round feature) so its clear what your original intention was. Solidworks allows you to switch between different windows with open sketches with ease, its makes life alot easier.