We have their wooden one that is just vertical rails.. he pulls up on them but there is no was he can climb out using the actual play yard and we are always around to make sure he doesn't try standing on a toy. We bought two of these and an extension kit so he has an 8x6 baby jail or smaller depending on the configuration we use. Late we'll break it down and use them in several locations like fireplace and windows as we have low profile windows I want to keep him away from. We got an awesome deal on the first one and went ahead and got the additional ones because we loved it so much.
Worth every penny, Amazon does great deals on these, if you add it to your shopping cart and then keep track as the prices fluctuate on a daily basis on a lot of amazon goods, you should be able to pick these up at a decent price. Like these way more than the plastic ones.
Would highly recommend this baby jail form North States.