I don’t think you’ll notice much drop in performance in the summer, my wife has weatherproofs and the only thing I’ve noticed is a slight increase in tyre whine, but only on very smooth roads at lower speeds in hot weather.
The downside of weatherproofs, at least last year, was they are not generally imported so I had to buy mine online and got a local garage to fit, which does mean you get stung a bit more on the fitting charges.
The weatherproofs are probably the most aggressive all-season tyre but also seems to get the best all round ratings.
If its not a particularly powerful car, take a look at the Kleber Quadraxer, another all-season and made by Michelin.
It sounds like CrossClimates are all-season with a summer bias, Weatherproofs are all-season with a winter bias.
After having various combinations of winter and all-season tyres over the last few years, I don’t think I’ll ever buy a ‘summer’ tyre again, a small trade off in the summer, for a big advantage, particularly when its slushy/icy, in the winter.