I've used Pheraplex and SD many, many times, including the original Pheraplex 3-4 times.
Pheraplex, while good, was nowhere near as potent as SD...in any area. It didn't cause as much muscle or strength gain, vascularity or fullness...and it caused some sub-q water retention (you don't look nearly as good), while SD makes you dry and hard.
Back when quality versions of these two drugs were readily available legally, Phera was ALWAYS considered to be the weaker of the two. That's why SD was much more popular. People liked Phera, but there just wasn't any dispute as to which one was was considered the stronger drug. The general consensus was pretty unanimous.
Some people liked Phera more than SD--not because it provided better results--but because it was more pleasant to run. Side effects like lethargy and appetite suppression were less common. Pat Arnold commented on Phera many years ago, saying it was about equal to Dianabol in potency (I would say that's a pretty close assessment)...and he didn't like SD, so he wasn't biased in his evaluation.