Howzit Shane...
I was hoping that someone with good insight into the Yelds would offer some pearls of wisdom. I can't, but I can tell you that the Yeld is one of the most respected hulls on the SA market.
They are heavy, so motors, towing, launching etc are a consideration, but it is potentially a life long boat.
You must just be quite sharp when buying.
If you have time, skills and tools, you can buy at the bottom end, do flotation, deck, transom and finishes yourself. That way you can be sure that everything is shipshape.
If not, then buy a recent hull with a know history.
I've seen too many boats that have been "reconditioned" by some backyard "expert" in an attempt to turn a quick buck. The scenario is often like this... You buy the boat after spotting an advert in the classifieds. The seller had "redone" it as a "project" and he's produced a flotation certificate. After your first trip or two, you find a bit of rot and start digging round... you then find more, you pull up a small bit of deck and then usually, the horror stories really kick in.
But good luck and be realistic about your time and skills if you're buying at the bottom end.
The classifieds are full of "project boats" for sale by people who underestimated the amount of work to be done. If in doubt, take time, budget big and buy a newish boat who's history you can verify.