I have a Magnum .52 in a 6 1/2 pound Ugly stik and it has unlimited vertical. I agree that the low end is a pain to set, but the power is above all of the other .46's. I have not run or seen a ST .51 so I can not compare them. The ST .51 would be my second choice, just because of all the ST's I have run over the years.

If you do get a Magnum .52, wrap the low end needle with teflon tape, put the card at a low idle setting, screw the needle all the way in, put a piece of fuel tubing on the fuel nipple, gently blow in to the tubing, turn the idle needle out until you hear air coming out. This will get your needle setting close right off the bat. The setting from the factory is 3 turns out. Mine is set at a spot between 1/2 and 3/4's of a turn out. I did this and broke in per the instructions and mine runs great. Some people have romoved the baffle from the muffler to get more power, I left mine in becuase when I ran it without the baffle it was way to loud.

Dru.

P.S. what I said about setting the idle needle can be used onany engine, it is the way ST does it.