Insane lift bags....worth it??

I have been seeing these Insane lift air bags for a while now, and I was wondering whether or not they were worth the $110 everyone wants for them. To me it is a good alternative to buying a $400 cantilever attachment for my 4-link, plus I need the extra lift to clear the 20's I plan on getting this Winter. Also I see that the compressed height is 3 1/4"....what is the compressed height of a Contitech or a Firestone 2600?? Thanks in advance for your help.Chris