A waterford bit - lets just say OUCH. These are jaw breakers. The bit wraps around the horses lower jaw - and lets just say, Yeah, I'd try to escape the pain too if it were in my mouth.
Sorry, but if you have to use a bit such as the Waterford to get your horse to lighten up, then you aren't riding him correctly. The reason why a horse pulls and takes the bit, is because they are NOT BALANCED
The pressure from this multijointed bit just makes the horse evade the pain up front, when in all actuallity, your horse still IS NOT balanced, nor working properly. You take this gimick away, guess what - your horse is back to where they were in the first place - leaning into their riders hands, because their rider has no idea how to ride seat first and start back to basics with the Training Scale.
Yep, it's a quick fix. Doesn't solve anything in the long run.
Of course if you misuse the bit (see sawing, pulling) it is going to be harsh; but so would any bit.
I do agree that NO BIT will make a horse lighten up in front; at least not correctly.