Maybe we could make a separate forum thread where people post their bots and discuss them.
That's a good idea.
(half the distance leads to 1/4 the profit but 4 times more trades [and more mtgox fees, so it would actually be less profitable]).
Correct me if I am wrong but Mtgox charges a 0.6% fee per trade so it makes little difference whether you make large* or small ones. But, as you say, you do need to ensure that you make approximately >(0.6*2)% profit on trades or you will simply be slowly giving away your account to Mtgox in the form of fees.
* Large being relative here.