I am looking to buy a free standing punching bag (can't get a hanging bag because of apartment rules and lack of space for a hanging rack) I was wondering if anyone had ever used any of the following bags and could tell me what they thought of them:

King Cobra Free-Standing Heavy Bag by RingSide
http://www.ringside.com/DETAIL.ASPX?ID=24721

Free Standing Heavy Bag by RingSide
http://www.ringside.com/DETAIL.ASPX?ID=24650

Everlast Free Standing Heavy Bag
http://store.titleboxing.com/title-e...-heavybag.html

Free Standing Wavemaster
http://www.ringside.com/detail.aspx?ID=25507

Thanks.

Alex