I'd certainly agree with the Cap'n.
They are of similar height and "build". The Connoisseurs, although still very nice figures, are showing there age, are a little "rougher" and are not quite as detailed as the Perrys. They tend to be in a very limited selection of poses, especially the irregular types like the Mahdists, but all the basic poses you'd need for company/battalion scale gaming are there. Considering how long ago they were sculpted, they are remarkably good figures and a taleted painter could really make them look comparable to more modern stuff.
This thread has reminded me I have a couple of bags of Connoisseur Sudan British infantry somewhere, which I have been meaning to clean up and paint for a while. I will happily use them together with my Perry stuff, but in separate units.