I use the marseinne twist .dll produced by a BB community member (i'm sorry I forget who) which i've upx'd and that makes it only 40kb extra in the distribution - but it's a huge amount to add to filesize for something the language already has...
That was ME! :)
And yes, I too am loathe to add it to a project just for that reason. Why add a dll for something the language is supposed to have already? But 40k certainly isn't much.
Torque2D also has the same issue. I sent them my C++ code for the mersenne twist dll, but I don't know if they used it or not in the last update. They did state they made some changes to the random number generator though.
It just blows my mind that something as integral as random number generation isn't done RIGHT in all cases.