As far as i know it isnt that they shit the bed its that they dont perform. From asking questions of those having issues it seems like the majority of his issue is shit or off the shelf domes. Its an incomplete package that doesnt put out.
When i ported my stock cylinders i had it running pretty good but it just never seemed quite right especially in the midrange and coming onto the pipe. At the time i just had a milled stock head so i send a spare stocker to mull to have rechambered and it made all the difference in the world. the midrange and transition was crisp and it pulled high and hard for relatively low port timings.