The TRT preference for Cyp that you talk about doesn’t come from the patient it comes from the medical professional that prescribes it. That preference is usually also specific to the geography that one resides in. In the United States its Cyp in in other parts of the world it’s something totally different. In the UK I believe its Sust (could be wrong someone correct me if so).I would chose cyp for TRT just because usually I find that most the guys on TRT prefer test cyp. And I figure that it is because it's less injections if they are doing it once a week. I could be wrong. I find though that a lot of guys on TRT are sick of injecting all the time and just want to inject something once a week.
I consider cyp usually as a ester that is injected once a week. And I consider test E something injected twice per week. That is just what I have noticed the majority of people doing. So I figure injecting test E twice a week gives more stable blood levels. And test C once a week might not be as stable of blood levels but it seems that's what most Doctors give patients still is test cyp. If im wrong some one correct me please lol I am still just here to expand my knowledge Im not a die hard believer in what I have stated. It just seems like what I have noticed.
Test C and Test E are very similar compounds with almost identical half-lives (Test C being slightly longer), for the most part, I would say they are interchangeable. The only thing of note is that you might have to adjust your PCT start date by a few days longer with Test C, but that is about it.
This stability that you are talking about with the 2 compounds is typically achieved through dosing frequency. A lot of TRT guys will inject twice a week for those desired stable blood levels that you mentioned. Persons running a cycle will usually take injections twice a week anyway due to the sheer volume of compounds they must inject.
The only advantage that I see when it comes to Test C over Test E is when it comes to the UGL scene, it usually has less PIP. I hope this helps.