New team builder doesn't let you preview a comp before joining

I think the new team builder is really cool. I'm so excited about it being an option for ranked so I can finally be sure to get a role I'm not terrible at.

But please let us leave at the screen where people indicate what champs they are playing without penalty/losing your queue position. Or if you must, make the old team builder an option for nornals.

I wanted to try out a sustain sup to see how bad off they were with the mana changes and thee new grievous wounds item. I get in and we've got a riven top, assassin jgl, squishy mid, and a Kog'Maw adc.... I would have gladly waited another 5 minutes to try and get a team comp that wouldn't force me to go tank sup.

I also imagine it's a pain for people who want to play off meta picks without upsetting everyone.