Glad it stayed together. Not real smart however even IF they never have a problem.
Do the math. Then ask the top manufacturers what the actual critical speeds are.
IF they'll even admit to it...because they usually side-step the question with some BS about quality and spin balancing...they'll tell you that due to the design and material that the shaft will have a lower critical speed than factory and as such your top speed will be limited if installing that driveshaft.