The Fusion 2 is one of the toughest tyres here, thanks to its dense Kevlar grid under the tread. The rubber is also quite thick there. While Hutchinson claim no reduction in performance, it was the second slowest roller.
It's not that it's particularly heavy but rather that the tread section is quite stiff; it lacks the suppleness of the fast tyres. The coarser 127tpi casing could contribute to this. It's not by any means a slow tyre. However, it's definitely one for your road bike rather than your time trial bike, especially where dependability matters more than all-out speed.
Like the Continental GP Supersonic, but for opposite reasons, you need to weigh up the compromises. Interestingly, there's also a tubeless version available (£36.99).