FmGo 11 does work ok over lan as you have stated, but for better wan performance you should consider FMGO 12. Fm 12 has been redesigned with wan performance in mind and it really does make a difference. Another point to consider is to create a stand-alone interface file that lives permanently on your device and have it use a file reference to your hosted data file (seperation model). This way only record data will be exchanged instead of record data, layout elements and all of the other 'bits'. The net result should be to exchange as little data as possible, and by having the layouts stored on your device, graphic data won't need to be sent via 3G. There are other things to consider such as only showing fields thay you REALLY need, and try to use merge fields in list views instead of normal fields. Each one of these techniques will add up to a significantly faster solution when being used across a 3G network. I have done the hard yards and been through what you are experiencing and when you start to rethink your design in a way that 'less is more', you will start to see good performance using FMGO across a 3g network.
Hope this helps, regards, Lee.
An absolutely brilliant answer - thank you very much!
Would it be ok if I post your response (with credit) against my identical request on FMForums?