A common mistake for RM files is to leave the settings at a very low bitrate which is common for streaming off web pages, set for 56K modems or less. Try rendering at either 1 or 3 Mpbs and the quality should be excellent while still keeping very good compression. Of course this high a setting won't be suitiable for streaming unless you know your visitors have broadband. It is however great for general use if you plan on playing the files off your computer for personal use. If quality is also low for AVI, are you using navite uncompressed AVI or one of the variants that is compressed?