Because sus has prop it's effective immediately so it could be regarded as a nice "jumpstart" compound but that's about the only advantage (besides the dosage) and not much of one because even enth will raise T levels within 24 hours. Sus is a strange beast. It's kinda cool that it has different esters released at different lengths but ultimately, it's pointless once multiple injections are involved.
The enth/cyp thing has been discussed to death. For HRT, sometimes they give me enth, sometimes, cyp, no difference whatsoever. I'm not sure why cyp exists. I think they wanted to make a longer lasted ester but it doesn't really last any longer than enth. Some will argue it lasts for 12-14 days as opposed to enths 10-12 days. Some claim less water on one or the other, but it's all speculation and hair splitting for the most part. They both do the same exact thing. A good workout and a good meal will make more of a difference in your results.