Best file transfer solution/product

Question

we are looking at a commercial product for transferring files over web . the application should be able to :

1. Should have APIs to Upload/Download files
2. Should have APIs to notify feedback in terms of progress,success,failure
3. Should have APIs to support check point restart.
4. Should handle large file size upto 10 GB.
5. Bandwidth throttling should be a good to have feature.

if anybody as good experience in any product suiting above requirement,please advice.

also any comments on BITS 4.0 from windows.

Thanks in Advance DEE

Answer 1

Assuming .NET, NeatUpload has worked well for me in the past (very distant past that is).