Have made connections w/8320 Curve from TMo to UMA via hotspots at home and @ Starbucks. Phone calls clear, data connection great.
Setup new wi-fi connection at a family member's house this weekend. Get data connection OK and "UMA" indicator (not "uma"). Signal strength varies from one to three bars surrounding the antenna logo. For all situations though, phone calls after connection are choppy and unintelligible. Is this a connection issue to the router or something to do with the speed of the internet connection?
Based on the bandwidth available, you should be seeing much better performance from UMA vs EDGE.
What you were seeing at home or at a good hotspot is what you can expect when everything is dialed in correctly.
First guess is interference. WiFi uses a number of discrete channels to reduce interference with nearby devices.
Use the Site Survey tool, an option under Wifi Diagnostics, to identify the various signals in the environment. Note that each source has a channel assigned. The default is channel 6 and most routers default there.
If you have more then one signal on the channel, look for a clear channel and set the router accordingly.