The only down side to the brass is cost, at $2.00 ea it's not cheap, other than that, i've had little trouble with it. Decent consistancy (i do have to weight sort) & it seems to be well made, I have LOTS of firings on several cases w/o any trouble. If you're going to have one built, (to state the obvious

) you can pick any twist you want.... that big ol' case should really spit them 300grainers...
I guess there is one caveat... I have been shooting my Lazz' for years, it seems there were some changes made in the brass manufacturer, I have brass with 2 different sizes of head stamp, (the letters are bigger) I just found this literally this week. I am still testing to determine if there are any internal differences, since you will most doubtedly be buying new brass, you should have no trouble with this issue.