And OMNY will either accept a tap to pay credit card, a phone with tap to pay (including Apple's express card option, where it works even if your phone is dead), or a prepaid value dedicated OMNY card.

It does not actually run the transaction through the entire way - if a transaction fails, the card info gets placed on a blacklist and that particular NFC device won't receive an instant authorisation next time. Generally speaking, people don't have an easy way to generate lots and lots of fake NFC devices, so this hasn't been a problem for widespread fraud (vs just jumping over the turnstile).

The Clipper cards used by BART are 90s technology that took so long to fully deploy that it was outdated by the time most people started using it. There was a brief window where if you were an early adopter it was better than what was available in many places (or not-so-brief compared to OMNY, which came along a decade later), but unsurprisingly the things designed later have mostly improved on it.

The killer feature that also causes most of the quirks is that it can be used to make payments fully offline without allowing double-spending of balance. This is of course mostly a killer feature for transit operators rather than users. OMNY solves the same problem by just accepting that it'll occasionally permit free rides.

They replaced rechargeable mag stripe cards with sub-second processing time and near 100% reliability (unless the gate was offline).

I remember when the clipper cards rolled out. If I saw more than a few people holding one, I’d just go to the other gate.

I guess Clipper wasn't super reliable when it came out(?) (so long ago at this point it's hard to remember), but I don't really remember having much fondness for the old BART cards. (Not to mention the annoyance of having to pay for BART and Muni in different ways, or carrying around those silly paper Muni transfer slips.)

These days, I can't remember the last time I had an issue with my physical Clipper card. I do recall lots of issues when they first rolled out the ability to put a Clipper card on your phone, but I haven't run into a problem with that in at least a couple years.

I don't know if this is the case with BART, but I've seen in my own local public transit network an incredible inability or lack of will to use systems proven in other areas. Instead of going with quick, proven, and reliable, systems, they'll default to going for the cheap option, which is usually slow, re-inventing the wheel, and unreliable. I visit a city like NYC or London or Tokyo and see a transit system with decades of accrued understanding, technical experience, and optimization. Then I come home and ride something shiny but slow, janky, and bug ridden.

My one huge gripe with Tokyo's/Japan's transit system is that you can't load money onto an IC card using a credit card. I was just in Japan last month; my last trip before then had been in 2017, and I really assumed that they would have fixed this deficiency by now.

I forgot to get a Tokyo metro pass along with my train ticket from Narita to Tokyo, so I ended up wandering around Nippori station looking for an ATM that would take my Visa debit card so I could get some cash in order to top up my Pasmo card[0] and take a local train to Shinjuku. I'd also forgotten how most random ATMs don't take foreign debit cards; after it dawned on me, I left the station, found a 7-11, and used the ATM there.

This was not something I enjoyed having to do, while carrying my bags, after a 10-hour flight, plus 2 hours waiting in line at immigration, followed by another hour-long train ride to the city.

I was pleasantly surprised to find that many many more businesses in Japan take credit cards nowadays though.

[0] I was also pleasantly surprised to find that Pasmo cards are still good up to 10 years after the last time you use them. I feel like something similar in the US would expire after no more than a year or two.

NYC wisely decided to license London's system.

It works so well that I was severely confused the first time I used them, coming from the Bay Area. I spent ages trying to figure out how to instantiate and load a transit card into Google Wallet before realizing I could just tap any card I had.