Dynamic Q is really nice, but also has some issues, for example here's a couple i can think of.
Premades, love them, or hate them, they are there. If you want to play ranked, i really suggest playing with friends, or you will have a bad time, you will go against 2-4 man premades on voice chat, which have a clear advantage. And you will normally get just a duo if your lucky on your team(if you have my luck that is). I nearly always lose a match when it's against a premade of 3 or more, because they coordinate turret dives like it's the LCS at level 3 or 4, and with turrets the way they are, you can't do ANYTHING against the gank. And so they do this to our whole team and just always win and get ahead, which is really sucky.
Your role select, I like the idea of it, but it has clear issues that i just can't get over from losing Team Builder. In Team Builder, you could get the EXACT role, and EXACT lane and EXACT champion you wanted which was super handy if you wanted to practice a champ, or role, or even duo queue with your friend and get bot lane together. With dynamic Q, its a 50/50 on the lane you want, unless you pick fill or support, you will get support 100% of the time no matter what other lane you picked. You also can no longer rely on it to actually let you duo with your friend or in my case, your girlfriend.
Me and my gf loved to ADC/Support for each other, and now we can't because we hardly ever get the same damn lane together, and no one in this game likes to give up their lane. So that's really depressing.
Personally, i am more than willing to wait for a 5-10 minute queue if i know exactly the lane/role/champ i will get, So I LOVED Team Builder SOOOOO MUCH, especially to duo bot lane with my GF. And my queue times with Dynamic Q are roughly always 2-10 minutes anyway, so it's not like the queue times got improved at all, Especially when people can dodge in dynamic Q and you have to start the entire champ select process again which takes like 5 minutes at a time, multiply that by 3 or 4 dodges in a row, and boom you have wasted 15-20 minutes before even getting into a match xD.
Other than that, i really like it, it's clean and crisp, and i do like the champion select part with the bans and such, unless someone dodges over and over which will result in like 20 minutes of time wasted going through the champion select process OVER AND OVER AND OVER again, and besides what i stated above, i do like it.