I've never used it, I actually use a milk isolate 80% casein and 20% whey. I doubt if anyone can help you with actual numbers, I've never seen them. I saw one study that concluded digestion varies from individual to individual and day to day. On one occasion 100 grams of beef was digested in one hour by individual A but on occasion two it took 1.42 hours. Another individual consistently digested their protein within 2.0 hours consistently. The range for the entire group was from 1.0 hour to 2.0 hours for digestion of 100g of beef protein of which 70% was hydrolized upon entering the intestine where hydrolization continued.
The studies I've seen done with whey and casein have measured blood amino levels. Whey levels peaked in under an hour and fropped rapidly (within a couple hours). The casein was elevated in about an hour but remained elevated for over fours hours, peaking at three hours. Therefore it's hard to say how the beef compares to casein in maintaining elevated levels of amino acids. There are so many variables, including the size of the meal and composition that can modify times of digestion. It should be noted in the whey and casein study tehy were using leucine as a marker so more casein protein was consumed than whey which would likely modify times of digestion.
My point is that if you choose casein just stick with regular old casein or milk isolate and save your money.