Canopus ADVC-100 - 241.33
Canopus ADVC-50 175.07
DataVideo DAC-100 - 197.99
Pyro AV Link - 135.71

Which is best for video and sound

The negatives I have read for each:

ADVC-100 saturates red too much.
ADVC-50 has interference due to it being internal.
DAC-100 not as sharp.
Pyro has audio video sync problems...

Anyone able to quash any of these as being major problems?

I would go for the ADVC 100, but its very pricey so the next obvius choice is the 50 model, but will interference really occur?