They work great! I moved 4 times in the last year, and that was how I packed instead of boxes or bins! It saved so much room, and it was so easy to pack around.
Do buy the better brands thou. I tried the cheaper ones, I think Ziploc came out with something - but they eventually fill back up with air and defeat the purposed.
Use a vacuum to suck out the air...and it also helps to have two people there to push out the air (or sitting on it will work if you have just one). PLUS - when you open the bag, the clothes aren't even wrinkled!
Tip: once they are shrunk down, maybe then put them in a bin. The bags are hard to stack on one another as they are slippery! Also..."google" for space bag coupons - you never know, so sites have them! We got our at Home Depot on sale.
Have fun!
Leslie