Here are some other ways to speed up the connection (i.e. decrease the latency of the screen response):
1. Change the encoding options. I find that "Tight" works well over constrained bandwidths, but if the VNC server is on your LAN, that "Raw" encoding may work better. There are other encodings, such as "Hextile", "CoRRE", "ZlibHex", "Zlib" and "RRE" which may be more appropriate depending on your setup.
2. If your client offers allowing JPEG compression, try turning this on. This is CPU-intensive on the server, so if the quality level is adjustable, try experimenting with it to see if you're comfortable with the trade-offs between screen refresh latency and display quality.
3. Disable scaling, unless you need it. I find this is most useful for viewing a desktop machine from a handheld device, which has constrained display area.
4. Experiment with other supplied options like enabling CopyRect encoding and adjusting other custom compression levels.
Experimentation is key to optimizing your VNC connection.