VNC, PcAnywhere, NetOp, etc... are inherently *all* dangerous softwares because of their functionality. Personally, I hate PcAnywhere because of the complex communications aspects. VNC on the other hand can be classified as 'firewall friendly'. Just one primary TCP connection.
Is it a good idea? If you will use it for outbound, I believe there are no special risks. However, for inbound use you'll have to check if VNC has enough security in house to protect you from non-authorized use. So, it's up to you to decide if the benefits are worth the possible risks.