I have level 5 Summoners. Overall my experience with using bots is that it doesn't make that much of a difference if you play manually or let them play. At times when watching some of the battles, I feel I could have come up with better options, other times the bot comes up with really effective decks.

Most importantly for me it the time it saves no longer being stuck each day having to play for an hour but instead being able to play when I really feel like it.