Steven wrote an answer about La Sportiva Testarossa Vibram XS Grip2 Climbing Shoe on December 21, 2011
I've tried to answer this several times beyond the obvious velcro/slipper vs. laces dichotomy. After owning both of them I ultimately chose the Testarossa's and have stuck with them through three pairs now. The Testarossa's are hands down a much better edging shoe, while still maintaining much more sensitivity than the Solutions. They flex in a way that allows you to paw the holds much more, in addition to being better through tech slab sections. The Solutions are just plain aggressive from the get-go, you slip them on and it's go time, but the Rossa's are the most laid back aggressive shoe you can get. I don't even lace up my shoes half the time (I wear a 40 in La Sportiva and 10.5/11 running shoe) and yet they are there for me 100% through heel hook, smear, thin edges, etc. That being said, I am going to order a pair of Solutions again for a couple hardcore toe/heel-hook intensive problems that I want to send when the snow melts.