Entertaining thread, ill appriciate any successfull boot since my Jtag kicked the bucket and that's the only thing that matters to me really.
I am no expert and don't claim to be but I have nothing better to do this morning than through my thoughts in the mix. As mentioned there are two factors hardware and software.
Is been said "It requires precise and fast hardware to be able to send the reset pulse". So cheep poorly made boards with fluctuating voltages and delayed pulses mixed with an amateur poorly soldered install might miss the timing a couple of times before hitting it.
If TX are using what they claim to be a better chip don't knock them for it! Yes they wanna make some money out of it and get the upper hand in the market but if it gets me a more stable and reliable product then super duper!
It has also been said a "stable voltage" makes a big difference and the caps on V3 look chunky and capable of stableising the voltage well during boot.
A good feature for me is the two connectors on there and the switch (slim/phat) which would be handy for people like me connecting and disconnecting from lots of old boards. Ill be using my first board to regain lost keys from boards I have collected from ebay cons. Some of the clones require you solder pads on the board or connect your own switches to switch between

If I really did have to put some money down on a better board currently TX have my vote only based on
apparent functionality,
asumed reliability,
slim/phat adaptability and a bit of good old reputation.
Either way stick to the two big vendors if you want reliable support and potential updates.
But that's just my 2 pence!