This is what has worked for me...  I use The Stick and also a foam roller.

The stick is good for taking with you on runs or travelling.  It comes in a travel size.  Also, try and get one that is not too flexible...otherwise it will not roll the knots out of your muscles that well.

I use the foam roller for longer runs but I try to do it at home since it involves getting on the floor and takes about 10-20 mins.

But I don't have any experience with the other rollers...my trainer told me that if it doesn't physically hurt when you are rolling your muscles (especially your hip and TI band) then it's not working.  That is why I think that foam roller is so good.

I think the new Corbo Golf Ball massager works better than the Stick or foam massager. I haven't tried the FlexMassager, but people tell me they like the Corbo one better too and it fits easily in your gym bag. It also conforms to your body and hits all the pressure points causing those aches and pains. Try it! They have a 30 day money back guarantee. You can get it at http://www.corboindustries.com.