In order to test some very expensive lenses I usually go to Camera Rental Centre in Singapore and they provide very good service. Here is the website: http://sg.camerarental.biz
You can rent it for SGD50/day.
The new 24-70mm from Canon is heavy but was ideal for street photography during a trip to Jaipur. It delivers sharpness, color balance, minimum chromatic aberration and nice bokeh.
This was shot at 24mm f2.8
This was shot at 70mm f2.8