I don't think that "will it be too difficult for me?" should be an important consideration for you. This is because, at the basic level, configuring the 9400/9600s is similar to configuring the earlier TSUs (or any other all-in-one IR remote).

Rather, the key issue is "what do you want to use the remote for?". This is because there is no point buying an expensive 9400/9600 unless you want to have more than just have an all-in-one IR remote.

In some sense, the possibilities with the 9400/9600 are endless. The configurations are totally flexible in terms of activities, pages, layouts, macros etc. They can communicate by TCPIP and RS232 as well as IR and can thus communicate with your PCs and/or with equipment not in line of sight. And they are computers which can (but don't have to) be programmed in Javascript (note: not Java, and unrelated to Java), which means that you can do logic, computations, conditional clauses, interrogate web pages, etc.

I also had the earlier TSUs but can safely say that buying an 9400 was one of the best purchasing decisions that I have ever made. It is light years better and more powerful than the earlier TSUs.

Finally, the 9400 and 9600 are functionally identical. So the choice between them depends on ergonomics (e.g. tablet vs wand), screen size (the 9600 has quite a lot more pixels) and cost (the 9600 costs quite a lot more).