I have measured Cape Holes, and for my money, the best dogleg angle is between 20-30 degrees, no more. Some would argue for 45 deg., but one thing to recall is that any angle in the field looks far greater than how it is actually drawn on plan. The 60-90 degree seems to set up for an alternate fw carry shot instead.
My mentors had a pithy saying - "We only avoid sharp doglegs under two conditions - where there are trees and where there aren't." However, I have designed a few I really like, such as Tangleridge 14, which has a sharp DL, water on the inside all the way down and a wide FW. Basically, challenge the water and you can pick up 2-3 clubs vs. playing to the far side to take the water out of play completely, and it is about a 7 to 4 iron difference. Going from mid to long iron is enough penalty to make you think about not playing too safe off the tee.
However, generally, I agree and the most graceful doglegs are gentle, and it doesn't take a lot of angle to set up the strategy. Under 10 deg. or so and you can still see the green, or at least its outside flanking bunkers, which makes for a pretty hole. Get closer to 20 deg., and you have a real dogleg look.
Next question, what are your favorite double dog leg par 5 holes?