Ranking up fast - Diamond Reached

If you followed my latest post. You would've seen that I invested another $500 into cards. Add some bids that filled to that and we are talking about +/- $800 in new cards. Yesterday was the first time I rented a level 3 and 4 summoner. Level 3 Kelya and level 4 General Sloan were rented. I immediately got on a big win streak as my cards were totally overleved for Gold III. Following a 11 game win streak I suddenly ended up on Diamond III. This was new territory for me. I had to sleep a night to think about if I even wanted to level up to diamond as I don't have experience and I don't know what to expect. And leveling up means I can't compete in certain tournaments anymore. This morning I decided to give it a try as the new season is close and I want to play as high as possible.

This morning I also opened my first Diamond daily chest. My expectations were a little bit higher, but it is okay. We take any rewards.

Do you think level 4 summoners are good enough to play at Diamond in the upcoming season? I think I'll have to stick around Gold to win more games. Let me know your opinion.