There are people here saying that they have found good seeds, and I don't doubt what they say. The bigger issue, however, is that the whole PST 'thing' is not reliable anymore. For a very long time, you could reliably grab some jars or sachets from the supermarket and they'd do the trick. For bulk purchases, there were some stalwart brands (which I can't mention directly) but one was "Baker's XX" and another was "Sun XX". That latter one especially consistently churned out some of the best seeds I've ever had. Very strong, very long lasting, and pretty damn enjoyable.
For some people, myself included, PST represented an alternative to Subs, 'Done, or just withdrawals in times of need! For a good stretch of time I used only PST and only really used one or two suppliers. Quality did vary but was consistently high and would be enough to keep you well (unless you had a raging fent habit or something). This lasted years.
However, as of about three years ago, the reliability and consistency took a dive.
First there were Aus seeds which had been thoroughly washed and were essentially unusable as they were so weak. Then the market gradually switched over to imported seed stock (almost always from Holland and always low quality). I tried a lot of different places (both online and in-store) and wasted a lot of money during this frustrating time. For a time there were some good Indian seeds, but these were very inconsistent and sometimes even arrived rancid in broken packaging. There was some very strong Spanish seeds which were black as night, wet and clumpy, and had a very strong and off-putting smell. I never found these to be very satisfying but they were not bunk.
The worst development came maybe around a year ago when suddenly seeds which were labelled as Australian, and which looked, smelled, and mixed up exactly as expected, turned out to be 100% bunk. I have no idea what processing was done to achieve this, but if you made a batch of tea it all looked legit.... until you took a sip and there was zero bitterness. Just a kind of taste of tap water, dirt, and sometimes a soapy aftertaste. But absolutely no bitterness and no effects at all.