The installed copper seems to be leaking and bent.
there are actually disadvantages depending on the use. black pipe is typically used for natural gas, air, oil lines. type k copper is the thickest of its kind when it comes to coper for water line use - of course , it too can be used for air etc. type m, type l , and of course type k - copper should not be used in natural gas for it flakes off internally and will cause problems down the line - as far as leaks, copper can be repaired so i would recommend repairs -
what are you using it for water use copper where is it leaking at the joints . are you getting pin holes ussally caused by electrical grounding to pipe instead of grounding rod ussally older homes black pipe will rust and leak at joints in no time at all
