The best feature is that it does not require any manual intervention or effort to update our clients systems, this saves us substantial time in comparison with other products we have seen previously - so far there isn't anything i dislike about jetpatch (although their support team could be better).
It has helped reduce downtime significantly as well which was one of my main concerns at first but now I can happily say its been very helpful! We had an issue where some older software versions were causing issues for newer ones when updating them via WSUS/MS patches. By using JETPATCH all these problems are solved by just clicking "update" from within Windows client without having to manually install updates each day.