Trainer: Mag or fluid or ?

[jh_on_the_cape]

Looking at purchasing a trainer for the first time for this winter.
I have always wanted one, but now wife wants one so there you go.
I did a search but could not find anything here. I did find something on the REI website.
This is just for fitness, not training to 'win', but training to not get too far out of shape in the winter. Ride the bike while watching TV for 30 minutes.

Looking at sale stuff at nashbar. mag or fluid? or??? want to be quiet and store easily for summer and be simple to setup. no rollers for us.

mag for $72
http://www.nashbar.com/webapp/wcs/st...2_553418_-1___[Ljava.lang.String;@84470306

fluid for $96, worth the extra?
http://www.nashbar.com/webapp/wcs/st...2_556272_-1___[Ljava.lang.String;@84470306