Before Anyone Gets Upset.....
The loss of item sets are not that big of a deal. As a player that currently uses item sets in game the loss of one element from the legacy client is not enough for me to get super butt-hurt. Now I have read a bunch of the Reddit threads and Board discussions on this issue and really I only want to say one thing. GROW UP!
There I said it, I have been Alpha Testing the new Client since June of this year, and when I was brought on as a tester things were rough to say the least. Between all the random bugs, lag between the client and the servers, and only being able to play ARAM for the first month of my testing experience, I can honestly say I am super excited for the rest of the community to begin Beta testing here in few short weeks. The things that the new client has accomplished already and the plans Riot has for the client in the future makes League feel like a more immersive experience inside and out. We may be losing item sets, but we are gaining Training Mode, Replays, a better rune set up, a whole section of the front page just dedicated to the patch notes, a tab for esports, for people who play on a laptop like me (and most other college students) not having to use scroll bars while in the shop is a huge milestone. Now all of your conversations with friends are located in one central location instead of those annoying ass tabs along the bottom of the Legacy Client. And these are just to name a few of the really freaking cool changes. The random little nuances that still make me so excited to see people use the client so people can become as jazzed as I am about the changes leaves me excited for when this thing finally ships. I may not be a developer, but I am honored that I was able to be a small part of it. If anything Riot has gone above and beyond and I hope that you are all as blown away by the new client as I am.