Cannondale SAVE frame technology in entry price
All frames flex to some extent due to impacts or road shocks or vibrations. Some frames are better at absorbing this than others. All frame designers engineer their frames to attenuate these imperfections in riding conditions appropriately (for control/comfort reasons) by varying the size/shape of tubes and their compositions

SAVE is Cannondale's marketing term for this engineering. It isn't really honest to call it a "micro-suspension" anymore than any other rigid bike -- its just the frame engineer doing their job.

In a complete bike, you also have to take into account the rest of the bike beyond the frame like the saddle, handlebars, fork, tires, etc. in order to determine how comfortable/controllable the bike is. This is what you should assess the bike on, not some random marketing term. 

You should go for a test ride before deciding on a bike. You may find that a bike without some marketing term like SAVE is more comfortable or better value to you than one with that. Or, you may like a bike with it. It would not be advisable to base the decision on buying a bike based on whether or not it was marked SAVE (or equivalent from other manufacturers).