The Di2 will succeed where the S2 failed. Maybe. Remember faster is relative as you get older, the S2 kept you from getting slower. It succeeded in keeping you at the same speed, so hence it did make you faster. The Di2 will make you faster depending on how much time has gone by since you got the S2. You should have gotten the S2 and the Di2 at the same time. It may be to late to be effective.