I am looking to purchase a rollator for one of my relatives. My first question is: what is the difference in?

manueverability and also stability between the 3-wheel and the 4-wheel different styles of rollators available today. I am leaning toward the 3-wheel style only because it looks less medically debilitating and cumbersome. But, I want to know if anyone has tried both and, if so, which did they find safer and prefer?? The two different models I am considering are:

3-wheel rollator:

http://www.drugstore.com/products/prod.asp?pid=167288&catid=10&brand=50381&trx=PLST-0-BRAND&trxp1=10&trxp2=167288&trxp3=1&trxp4=0&btrx=BUY-PLST-0-BRAND

4-wheel rollator:

http://www.drugstore.com/products/prod.asp?pid=167271&catid=58721&trx=GFI-0-PLP&trxp1=58721&trxp2=167271&trxp3=1&trxp4=1&btrx=BUY-GFI-0-PLP

BOTTOM LINE: 1. Which is safest?
2. Sturdier?
3. Easy to maneuver around corners?

Thanks !!

Related posts:

1. I Am Looking To Purchase A Rollator For One Of My Relatives. My First Question Is: What Is The Difference In?
2. Difference Between Walkers Rollator
3. Cat Lovers Serious Question: How Do I Keep My Cat From Killing Me?
4. Does Anyone Know The Difference Between A Regular Walker And A Rollator Walker?
5. Auto Brake Rollator, Walker