Need an opinion about Navionics chips

What are some opinions on the best Navionics chip for Oklahoma & Texas, I bought a 2007 model fishing hot spots chip on EBAY and i am not impressed at all. A friend of mine has a 2006 model Navionics chip and it shows much more detail. My hot spots chip shows alot of the man made structure but not nearly as much detail on depth changes and does not show smaller creek channels. The Navionics chip my friend has shows ALL the depth contours and ALL the creek channels. I cannot find the same model chip he has so someone give me some ideas of what you think are the best chips.....

Come on guys I know someone has an opinion??????????? At least let me know what yall are running and tell me if your satisfied.

Try the Sonar/GPS Installation & Operation section

Thanks I will do that.