I bought ATC Simulator 2 first but I am happy I stopped using it and moved to London Control. Personally, I got them to get a bit of a feeling for the job rather than for the selection process. But I have to say that London Control and the visits to CCs/TWRs gave me quite a bit of material to talk about in stage 3 (more than what was needed anyway).
We'll see how realistic London Control is once I start college in April (It's fine for sectors and all that but... RT?
)