Sadly no. I have been using “Trickle” to manage the bandwidth of InSync.
If you use Ubuntu you can just download it from the Software Center.
Once installed I add the following to my startup applications command line: trickle -s -u 200 insync start
That limits my upload speed to 200KB. If I don’t use this, Insync is all but useless since my network gets saturated and nobody else can use it until the sync is complete. This really should be a basic feature of the application if anyone that has any say so can do something about it 