I haven't called anyone yet regarding the problems I've had since the update. Kinda afraid both Sprint AND Samsung will say it isn't their problem and can't help.
The day after the update, my phone couldn't make calls! It took 1/2 hour to get a call through to my spouse, who has the same phone. He also had trouble getting calls through to me that day.
I have found a few HUGE issues with the phone now. I have vibrate completely turned off for ring and notifications, yet my phone still vibrates at random times. There is no message or incoming anything, nothing appears to have crashed, but the phone still vibrates. Do not like!
I also have a problem that may be related to an app I downloaded, not sure. I really miss my Centro calendar. It had different colors for each category of event, so I could tell at a glance if I had a doctor appointment, a rehearsal, a vacation, whatever. So I downloaded 2 free calendar apps that I hoped would have that function. One I didn't like and deleted it through the Settings - Manage Applications. One was fair, and sync'd with the existing calendar. I also tried a "busy buster" app, but it REALLY honked things up - the "Home" and "Phone" menu buttons on the home screen disappeared entirely - it only has "Applications" now. I deleted teh busy buster app through the settings manage apps right away, and rebooted, but no good.... Still only have the "Applications" menu button.

We don't get cell service at our house, so whenever I leave home (once a week or so) and get into a service area, I shut the phone down and take out the battery as instructed by a Sprint tech.
I did this the day after I loaded this new calendar, and suddenly half of my calendar events disappeared and half doubled. I'm afraid to delete any more apps as I don't want to lose my appointments info again!
When I push the side power button to darken the screen and put the phone away, a pop up comes up for all the power modes - airplane, power off, etc. Dude, I just want to put the phone away with the screen dark, not turn anything off!
If I press the "Restore Factory Settings", do I lose all the apps I have? Some of them (NFL News specifically) are not available on the market any more!
Also, when I go on the Internet - there is no option to go to my home page! The order of my bookmarks are weird - there is no WAY the "Most Visited Site" on my phone is some LOLCat photo I looked at 6 months ago - but that is what is listed!
The "Task Manager" thing is weird as well. One time I exited the Internet, and the Task Manager popped up. The ONLY THING LISTED was "Task Manager"! WTF????
So I really don't like Gingerbread - can I go back?