Backup Mac OS partition to NTFS: are there any drawbacks?
If connected directly to your Mac, you may need to install something like MacFuse and NTFS-3G or Tuxera NTFS to be able to write to NTFS partitions. Per Apple Support:


  Mac OS X can read and write FAT volumes, but can only read NTFS volumes.


If the drive is connected over the network, then your main issues will probably be network speed/latency, authentication, and the size of the backup data compared to the size of the drive.