I have been using the Salming Race R1 shoes for a little over a month and I am very impressed with them. They are a very light pair of shoes. I have found them to be very comfortable. They grip the squash court floor very well and provide the support required for the hard movements we as squash payers make on court. They are a terrific pair of shoes for squash.
The top of the shoes are primarily a mesh material with an EXO Skeleton structure around that to provide the required support. Being mostly mesh definitely helps keep them quite light. Light shoes for squash are a definite benefit. They have to have the strength though to support the hard directional changes squash player makes though and they do.