In general, esketamine has been shown to have about the same efficacy as ketamine for Treatment Resistant Depression (TRD) and MDD. There seem to be some minor differences in bioavailability between esketamine and ketamine, but from experience, if one work, the other will, and if one doesn't, the other won't. Anecdotally, we've seen great results in a matter of weeks with patients who have had no success through numerous antidepressants, TMS, ECT, and other treatments.
There is a long-term trial now in its 4th year with esketamine (https://clinicaltrials.gov/ct2/show/NCT02782104). I'm not sure how much has been published yet, but early data I saw supported immediate relief and long term benefit over the 4 years.
In terms of it being a sinister ploy by pharma, it's definitely priced higher than its ketamine generic counterpart, but for the vast majority of our patients, ketamine treatment out of pocket (since its not covered by insurance) is absolutely unaffordable, and pursuing the insurer-covered version of treatment is a high-value option.