Many times. It's an epic course with very rough pavement, amazing scenery, and a lung searing climb. Here is someone else's description of the course.
Milton, Rock Creek, Salt Spring Valley, Hunt, Milton Roads, counter clockwise loop. A 21 mile loop of fair to bad paving, two climbs and a fast twisty descent.
The Course, road by road:
The basic road map for this course is Milton Road, Rock Creek Road, Salt Spring Road, Hunt Road and Milton Road. The lap distance is 21 miles taken in a counter-clockwise direction.
The start is a roll out of the Barn area onto Milton road, heading south. The road surface here is excellent. You only go about 200 yards before you turn east onto Rock Creek Road. The road surface quickly degenerates to fair to poor status and the road is flat for about 1 mile. The road then climbs up at about a 5% grade through the feed zone. This lasts for about 600 yards. There is a small descent past the feed zone, still on poor road surfaces.
Then the major climb begins. The climb of Rock Creek Road lasts maybe 3 miles at an average grade of approximately 8%. However the last half mile is at about 10% and this is where it really hurts. The road surface the whole way up is terrible. The only saving grace is that the speed is low so the hammering is less.
As you crest the hill you emerge onto a plateau. On the left is the Salt Spring Valley resort and lake. The land is flat and the wind doth blow. If you have slid off the back your chances of getting back to the pack are slim due to the wind. The road surface improves however and stays reasonable (fair to good) for a good few miles. You continue east to the hamlet of Felix.
At Felix you turn left through some gates (it looks like you are riding into a farm yard) and turn north onto Salt Spring Road, a long (4 mile) road at the head of the lake. This road is dead flat. The wind will entice the pack into forming echelons but for the individual rider it can be miserably hard.
At the end of the road it rises up about 50 feet and then you turn left and west onto Hunt Road. The road surface is average to good and maybe you will have a tail wind. The road joggles with 4 90 degree bends along it's length, but the gradient remains minimal to flat. After about 5-6 miles the road veers to the southwest and begins to climb. The climb is not so bad, maybe three quarters of a mile at 7-8 %.
After this climb you begin the descent back to Milton. This is a really fast descent. I do not recall any tight corners or curves, but the road surface is again pretty atrocious. I heard one rider describe it has a road to "knock the snot outta you". Only the brave descend at full blast. Your reward for this descent is that the road surface changes to silky smooth for the return to Milton. There are a couple of small rollers on the run in to town, and just before the last left turn onto Milton Road the finish is at the top of one of these.