Beta client too laggy

I know this has been posted a bunch of times already, and thank god I found out you can launch the Legacy Client, but here are my thoughts:

I'm creating this thread to show to Riot how much people are disliking the new client. I have all of the same lag problems as many other people have already discussed. This new client even affected me in game. When you alt+tab, the client and it's friends list/chat window is still open as well, maxing my cpu to 100% and causing me to range from 7-18 FPS while my ping isnt ever touched. **Yes, I have client animations and background music disabled, problems still persist.

My main thought as this: KEEP THE LEGACY CLIENT AS AN OPTION EVEN WHEN THE NEW CLIENT LEAVES BETA. I have spent hundreds of dollars on this game for skins and champions, and if I am forced to play in a laggy client that also lags my game, I will forever be lost as a customer, and more importantly, as a player.

I am back in the Legacy client but my god, that new client was a horrendous experience and caused me to tilt before the game even started.

My short list of problems:

Champ Select: typing in chat box is laggy, takes multiple seconds to appear. Should you type, hit enter, and keep typing, it can take a full 5-10 seconds for me to see any text what so ever, in the typing box or the player chat box itself.

Champ Select: unable to edit masteries. Should you even successfully change one or two, such as your keystone, good luck being able to Save your changes before the timer runs out.

Champ Select: changing summoner spells at first only causes half the window to appear with only a few spells showing. clicking one then takes forever for the window to close.

Champ Select: the time between searching for a champion and seeing the result takes roughly 5-6 seconds to filter the results

Champ Select: selecting a ban does not guarantee the client will let you click Lock In. Same goes for actually selecting your champion, let alone selecting a skin for that champion.

In Game: a separate client window runs in the background, causing in game lag. An updated client SHOULD NOT BE IMPACTING GAME PERFORMANCE.

So please, Riot, as someone who started playing near the tail end of Season 3, please, give us the choice to keep the Legacy client without forcing us to upgrade when the Client leaves Beta. I understand it is Beta and issues will be resolved, but I will stop playing entirely if I am forced to use this laggy POS.