I did the OEM NAV and yes, if I had to do it again, I wouldn't. Especially today with all the features that newer HU have (music streaming, smart phone synching, TRAFFIC, HD radio, higher DEF screen, updated maps, better access to porn, etc, etc.............. i know i know, but wouldn't that be great???!! LOL).
OEM Toyota navs are going for $700-2000 on fleabay, so yeah, not really worth it. In fact, I'm thinking of taking out my E7009 for a new aftermarket NAV with all the toys. Pretty confident I can get about $700-900 for mine.
Good Luck!