I consistently get high CPU usage on Windows 10 after returning from suspend. Insync consumes close to 100% of one core in my older Dell E4300 laptop (Core 2 Duo), putting it on the verge of overheating and I must close and restart Insync to remedy. Now using version 1.2.18.
Happens whether updating a file sync or not. After restarting Insync, CPU usage drops to near 0% unless syncing, then just a few %.
Otherwise very pleased with Insync, using as well on my desktop Linux box (Ubuntu 14.04, quad-core) which returns from suspend with no issues.
I am also having a similar issue on Windows 10 as well with insync version 1.2.18. My laptop is an HP G61 (Dual Core) running Windows 10 Pro. I always have to close insync then exit then open it again to remedy the issue.