Usually, at least when it comes to standard networking (should include FTP, not sure), the individual packets are all verified, so if the request is good the file output is good...so the program is the limitation. Filezilla has long been in my arsenal will no complaints, and if any one had any, I'm sure by now they have all been addressed.
Like CJPC said the initial section is the most vulnerable to corruption, BUT for those who would like to check, we have and extensive MD5 database growing between me and red8316
My part
red8316's part
Original Thread