Here are my thoughts on this phone. Lots of features for the price. Overall, works very well. Find some of Samsung key strokes awkward, compared to other phones.
Absolutely "HATE" the track Pad. Easy to end up completely some where other than where you were with the track Pad. Unable to load and read Qioo books because of the Pad. If they had put a normal compass switch on this phone I would probably continue to use it.
Most all my issues with this phone with the Pad. The problem is the Pad is used for most anything you do, so you can't simply avoid using it. Going to run the phone out of minutes and put it back in the box. I'm going back to a flip phone LG 440g. It's already in service and working well, so the transition will be a smooth one.
Other reviewers have reported all sorts of issues with pocket and purse dialing, and worst of all, calling "911" all by itself. I haven't had any of that happen to me, but I turn it off, before taking it with me. This would have to be the second big issue with this phone. If you can't trust your phone, NOT a good thing.
The S390G could have been a GREAT PHONE, but having two major flaws are a deal breaker for me. Fun while it lasted. Your experience may be different, and your mileage may vary.