Never used a Hex beam but I would hate to see you spend the time and money and have someone enforce the rules on you and have to take it down. Most beams attract attention period. By the time you get them up high enough they are quite visible as is the structure required to support them.
I have dealt with HOAs and the jerks that run them before. Busy bodies that have nothing better in their lives to play neighborhood cops in my opinion.
How about a vertical with a tuner? That's all the SteppIR is. Take a look at the Specs on the Big or Small IR vertical.
I know many that have them and some the are in very restrictive housing projects and they go unnoticed.
I finally bought property with no antenna restrictions whatsoever and now we are looking at selling and hitting the road. Oh well.
http://www.steppir.com/Technical.html