For the philosophers: If you have a euphoric buzz that lasts all day, but then you can't remember, did it really happen?
For the pragmatists: No, but the bad parts did (citations to appear before a judge, totalled car, angry romantic partners, friends who now treat you like a clown, herpes).
^ BTW, I agree: equivalent dosing to alprazolam, but less often. Risking repetitiveness, most subjective reports are of MORE amnesia at equivalent dosages than alprazolam or any other benzo, for that matter.
Also, everyone makes a big deal of the 60-hour half-life. (I'm not sure how strongly to believe that figure anyway, since this drug isn't all that well-researched.) And, yes, that's long...
But: (1) 1/2-life is not the same as onset/duration of action, which, AFAIK is much shorter as a rule; (2) many other commonly-used recreational benzos have long half-lives, in particular clonazepam, reportedly 18-50 hours, and diazepam with it's 20-100 hrs. (See wikipedia or just google "benzodiazepines half-life equivalent dosage" or some such.)
Besides poorly measured dosage, I think the main distinctive quality that people are recognizing as bad in phenazepam is the greater likelihood of amnesia. This side-effect is certainly variable across the benzo class, and AFAIK is unrelated to half-life (aside from duration of amnesia).
Even so, with some mis-steps here and there, and using great caution, I have found it useful as a "utility" drug (i.e. for its intended therapeutic purpose).