The strength of the hardware matters only when the programs are making heavy demands on "crunch power". When these programs are using just their "go knowledge based AI" and not a "MCTS evaluator" a reasonably powerful ipad probably plenty of hardware power.

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I found the fuseki play of Champion Go to be much stranger on phones than tablets than on PC.

Edit: Actually, I'll take that back. Rechecked both apps. Both seemed to play similarly when I tested there.

As long as these programs are still "playing by the book" there isn't even a difference between the "go knowledge based" AI's and the MCTS programs. All that matters is the size of the "book" and randomization strategies for selecting which of the book options chosen (I'd guess something like the same percentage of time chosen by the book games).

In both cases, divergence from the book will take place when a non-book move is made. But there may be some tricks involved (that allow for transpositions to be recognized).