4x4 Necessary?

Has anyone played on a table smaller than the recommended 4x4? If so how do you think it effects the gameplay? I have a card table that is 38 x 38 inches and I bought two 2ftx4ft Styrofoam insulation pieces and tape them together to make a 4x4 tabletop. I then have to tape the sheets to the table itself because they slide. (Its a pain to store them aswell)

I've personally noticed that when playing on a 4x4, the edges never really get used unless there are stationary crossbows in a building or something like that. It usually turns into a big brawl in the middle. Everyone's first turn consists of just run moves.

I'm just trying to see if I'm missing something, because as of right now I don't really see a point of having a 4x4, other than being out of range of crossbows, which can be balanced with more terrain.

Thoughts and experiences welcome!

I guess it depends on which scenarios you play.  Ambush, Defend the Find (and any of its offshoots like The Wizard's Mansion) and Breakthrough need that space or they just don't work.  

One of my friends has a cobbled together river canyon table that is really cool, except that it is like 3x3, so its not very useful for many scenarios at all.  We play a modified Street Fight on it, when he digs it out.

Just put some of that non-skid mat under the board, fixes the whole sliding thing