They are OK, and they are "fragile!!
DON'T bang them together, keep them lubed, make sure you hit the sprue plate square - or better yet, wear heavy welders gloves and just twist it open after the mould warms up. while it is cold you still may have to tap it once or twice.
They will give good service, but you have to be careful.
More than Lee, but cheaper than anyone else, is Jeff Tanner moulds. He will make any dia. you want, out of brass. Use lee handles, and they are the fastest mould to use I have ever seen. Cut the sprue later w/ dikes while you watch TV.
I cast so hot and so fast that the sprue crystalizes and breaks off even w/ the ball about 90% of the time anyway.