As above, it will run on HP just fine. LP is recommended due to the lack of an OOPS. When you screw the bottle in, the asa will depress the bottle pin allowing air to escape, which causes a lot of friction on the bottle threads and makes it hard to screw in. The LP output will do this to a lesser extent because of the lower pressure output of the bottle, whereas the hp bottle will take a bit of effort to screw in, and will suffer from more wear on the threads (unless you have the new SP SIS reg which has steel threads, so will be more resistant to wear). Performance wise, however, they're both fine. Many markers perform better on HP (though nearly all will run fine on LP at 10.5bps), however, so consider that you might change markers before you change bottles.