I stand by my advice that if you have to ask you should not try the b5 for kitesurfing.
As a 2-line open-celled foil it is very difficult to get to relaunch on land and impossible to relaunch if you crash it into the water.
If you want a good, safe, easy to use foil for land and water use you should have a look at Flysurfer Warrior, Boom Vector, and Advance Reha. These foils have a sheeting system similar to 4-line inflatable kites and also will work well on land. There is a page http://www.foilfest.com
which shows the advantages that these kites have over the old style foils.
If you do not care about water relaunchability or are on a tight budget, I suggest you consider some of the 4-line foils sold to kite buggiers. They are much easier to relaunch on land and can sometimes be relaunched off the water when you are both fast and lucky. On land the 4 line kites work better when you are underpowered so you will get more use out of one kite. It is possible to rig a 4 line buggy foil on a bar if you want to fly it like a 2-line kite and still have the ability to relaunch easily (on land).
Additionaly some of the good buggy foils are relatively cheap brand-new.
My opinion on the slingshot b-series foils is that while they offer high performance for a 2-line kite they are pretty damn expensive for what you get.