I have used both many times, and I feel the exact opposite--that 1-test is a far superior growth agent, mg per mg. I know many others that have used both drugs, and aside from you, all share the same opinion.
Anabolic ratings, although often highly deceptive, can occasionally shed some additional light on a drug's effectiveness. In this instance, 1-testosterone was shown to produce over 7X the muscle growth, mg per mg, than Primobolan...with Primo's anabolic rating coming in at only 88 and 1-test at a whopping 700.
So, in my experience and the experience of others, and when reviewing the literature, 1-test has been shown to be the superior growth agent. In fact, in my experience (and the experience of those I know), 1-test has consistently produced such superior growth results that I don't even consider them to be comparable. When I use Primo, I don't really grow at all, even with 500 mg/week. On the other hand, 1-test does add muscle tissue at a moderate rate.
I also consider it to be significantly better at promoting growth than EQ...with both real-world and clinical evidence backing up that claim.
About 10 years ago, when 1-test was much more readily available, I used it many times...and helped at least a dozen bodybuilders obtain the drug. Like I said, all shared the same opinion as myself, so it makes me wonder how legitimate your 1-test really was.
If you look around the boards at people that have used it (most reviews were put up years ago), you will pretty much see the same opinion reiterated over and over again. I believe even B-boy gave 1-test high praise on this board a few years ago. Primo has never been known as a good growth drug. On the other hand, 1-test is one of the best "dry" steroids out there at promoting growth. It is not a "mass-builder", per say, just as tren isn't considered a "mass-builder"...but I feel tren and 1-test are right up at the top of the heap in terms of growth promotion, when compared against the rest of the "dry" non-methylated AAS.
Lastly, I would go so far as to say that I have more experience with 1-test than almost anyone else that posts online. I was all over this drug when it first came out about 12 years ago...and used at least 7-8 different brands for 10-12 cycles. One of these was raw material obtained directly from a now non-existent supp company (1-test used to be sold legally), which had all their 1-test tested in US labs for both purity & potency. It was pharm-grade, as much as it could be. So, I've used my share of both good and bad 1-test. When good, it is one of my favorite steroids. Side effects (at least from an external and perceptual standpoint) are minimal. In fact, I don't really get any side effects from it. It is my "tren alternative" when I don't feel like dealing with tren's shitty sides.