Like many of the F series owners here, I purchased my 700 within the first month of it being released. I owned a Z1->Z3 prior.
First Impressions: The unit looks great, the iPod is much faster than the Z series, the bluetooth works great. I love the variable key colors and the GPS looks nice, but the bootup is horrible and the response time is sluggish. Also the iPod connection failed at least once a day. 4/5 Stars
After the 1.0 update: Not much of a difference, but it does work for the things I use it for, so no complaints. This is also where the hacking started, and made me love the unit. 5/5 Stars
After the 2.0 update: Noticed a better boot time, but the response time is still bad. I don't like pressing a button 3 times to get it to work. iPod no longer fails however. 4/5 Stars
Sold 700, purchased 90: Biggest mistake of my life. I bought it for the High volt preouts and msn direct (I don't care about the DVD player) and the MSN direct is horrible. Gas prices doesnt show a station within 18 miles, the 3 movie theaters I go to don't show up, 75% of the time I can't get a weather forecast, and the traffic info only gives info in the brooklyn queens area. Also I had to make a train and the GPS told me to make a left onto a right turn only road, with a divider in the middle. WTF, it took me 3 miles out of the way because it couldn't give proper instruction. I don't have any mods done so I'm using a basic F90 POS. I'll be selling it as soon as the DNX 9140 is released. 2/5 Stars.
If you are reading this and have not yet ordered the F Series, I suggest you at least wait until the 3.0 update and/or the Kenwood DNX 9140 releases. See what else is out there and read reviews until your eyes hurt.