Tests and benchmarks can be done by using the JavaScript console.
Use the command: 
sudoku.test.runTest(Object) where Object is {SQUARE: digit}

or you can use one of the predeclared tests: 
sudoku.test.runTest(sudoku.test.grids.easy.svd_1)

You can also test an entire predeclared group by using:
sudoku.test.runGroupTest(label) where label is one of the labels in sudoku.test.grids
"sm" for example.

Best test results:
==============================
Group Test: easy
Browser: firefox 4
Date: June 3, 2011 5:50PM
==============================
project_euler_1: [SOLVED] in 0.016s
project_euler_2: [SOLVED] in 0.016s
project_euler_3: [SOLVED] in 0.016s
svd_1: [SOLVED] in 0.016s
SUMMARY (total time: 0.064s)
4 [SOLVED]

==============================
Group Test: SM 
Browser: firefox 4
Date: August 6, 2011 01:11AM
==============================
sm
SM_1: [SOLVED] in 0.019s
SM_2: [SOLVED] in 0.094s
SM_3: [SOLVED] in 0.013s
SM_4: [SOLVED] in 0.016s
SM_5: [SOLVED] in 0.009s
SM_6: [SOLVED] in 0.016s
SM_7: [SOLVED] in 0.012s
SM_8: [SOLVED] in 0.011s
SUMMARY (total time: 0.19000000000000006s)
8 [SOLVED]

==============================
The world's hardest sudoku? Arto Inkala
http://www.guardian.co.uk/media/2010/aug/22/worlds-hardest-sudoku#
Browser: firefox 4
Date: August 6, 2011 01:11AM
==============================
world_1: [SOLVED] in 0.029s