You thought the old client was bad? It's nowhere near as terrible as this new abominable excuse for a client.
Please, give us a choice whether we'd like to downgrade to the new client or not and don't just shove it down our gobs.
(This may seem like a baseless grunt against the new client, without giving any reasons as to why I loath the new client, which Riot says they will ignore. Which means they don't have to consider the simple request "Please, give us a choice". A request shouldn't need a paragraph of justification because it's just a request.)
A large and perhaps dominant percentage of your playerbase.