Thought I would share my experience with the MFT 3.5.1 update. Before I was on 3.0.2, and had a world of problems. Laggy, bluetooth connections constantly messing up, settings dropping, continuous resets, just a whole world of hurt.
So, a little over a week ago I went to my dealer to get an oil change and have them do all the updates. Took a few hours for everything to get completed, but afterwards, following the update and a master reset I was starting fresh on 3.5.1. To this point, I have no run into a single problem, knock on wood. Here are a few of the big things I have noticed that seem to be fixed. For reference, I am using a HTC Incredible 2 phone running Android 4.1.
Media Player:
1) Bluetooth connections and audio connect much faster and are more reliable. After numerous short trips of hopping in and out of the car, the system never seemed to get messed up. Previously on 3.0.2, the entire MFT would basically give up by the 3rd restart in a short time and I sometimes had to just delete the phone and re-add it after rebooting the MFT system.
2) When selecting bluetooth audio now, if the device hasn't been detected it will detect and start playing. Previously, you had to click to detect, then return to the homescreen and then select bluetooth because the option got stuck highlighted. This is now fixed.
3) Also both the FM radio and Sirius seem to search almost 2-3x as fast which is a welcome relief from the mountains of lag before.
Phone:
1) Phone call audio, dialing and phone book seems to be fixed. My phonebook now doesn't auto-delete every 5 minutes like it did in 3.0.2.
2) Audio call quality is miles better. People didn't even realize I was on the phone. One person even said "Oh wow, I thought you were talking into the phone, because your car audio was terrible before but I just didn't want to say anything." Also calls seem to reliably connect and answer more quickly now.
Climate Control:
1) All the climate control stuff seems to be working perfectly normal.
Navigation:
1) New navigation is much faster and smoother than before.
2) I was having tons of reboots when navigation was used for an extended period of time before. Now the system seems to be very stable.
3) On the home screen the navigation displays the current street you are on regularly. Before, in 3.0.2, this was really hit and miss if it ever worked. It seems to be fixed now.
4) Entering and finding locations, especially when using the on-screen keyboard is MUCH better. It is now fast and smooth. I've also noticed the layouts seem to be better in the menus.
5) All of the new menus, and the new navigation layout are really nice and work well. The settings are much more convenient and easy to use now. Also zooming and panning is faster than before. Panning is still a little slow but, all in all, it is a lot better.
6) Lastly, the maps load much faster now. There is still a slight delay as they are read, but they appear correctly much quicker.
Overall Interface Changes:
1) The clock and a few settings, along with outside air temperature are working.
2) The messups on the homescreen seem to be pretty much fixed from what I can see.
3) The animations all seem to be either significantly shortened, or largely removed. This makes the whole interface much more snappy and less frustrating.
Other Possible Changes I noticed:
Not sure if this was part of 3.5.1 but I noticed that the dash-display, the area directly in front of the wheel now responds much faster than before. A lot of the animations here seem to be sped up and shortened. So overall everything feels much smoother.
Conclusion
After playing with the update for a week (and really trying to screw it up) the system is still moving along strong. I haven't run in to any reboots, and bluetooth and everything are still without problems. I was a little hesitant to get the update, but I have to say that the difference is night and day between 3.0.2 and 3.5.1. I am finally not pissed at my MFT system when I wake up every morning. There are probably some changes that I missed, since I don't use everything, but this is an update you don't want to wait or pass on. I'd try to swing by your dealer as soon as you can. Now that my transmission ironed out, and the MFT update fixed most of the system, I have to say that for the first time since buying the car this summer I am really 100% pleased (or at least 99%) with my purchase of this vehicle. Really starting to love this car now!!!