As long as communication speed isn't a concern for you, there is very little difference between the 3a and 3c / 3mx. The most useful improvements in the 3c / 3mx are a few software tweaks. You can make the necessary software tweaks to your 3a by picking one of the freeware or shareware programs from this table - which, in many cases, gives you better than the built in 3c versions. Which ones did I use on my 3a? JBData, ThreeT, BusyView and Fastnote. Which ones do I still use on my 3c? JBData, BusyView and Fastnote.