I prefer iGuidance 4.0 from iNavcorp. The maps are clean with good text detail and POI. The entire US fits in a 1.3Gb space (with plenty of room to spare on a 6-12GB Microsd card). Text to Speech (reads out full street names and directions and not TURN LEFT OR RIGHT AT NEXT INTERSECTION) for street names is perfect and beats TomTom (non-existant TTS) and iGO (non-existant TTS) (probably Garmin too). The ability to try a demo run with the GPS off is nice as it allows a turn by turn preview indoors if the GPS lock is poor. I keep the iGuidance 4.0 Cab install file on the microsd card and can reinstall the software following a ROM update without loading it back from a DVD and since it doesn't need a serial key to run, I am back up an running following a ROM update with no downtime at all. Currently using No2Chems NueRom 2 v5054.
It does need Fransons GPSgate to work properly with the Mogul built in GPS (hope that gets fixed sometime in the future... but it is a problem with the Mogul drivers and not the Iguidance software as the software works great with any bluetooth GPS unit I have used).
Links to the website and forum to make it work properly with the Mogul are attached.
http://forum.ppcgeeks.com/showthread.php?t=17032
iNav iGuidance website...
http://www.inavcorp.com/product/navi...e_software.php
http://www.inavcorp.com/product/gall...cd=3.%20%20PPC
Google Maps is great for a quick POI check if I am in EVDO signal range, but I still prefer to drive with Iguidance running.