I would have absolutley no problem with Dynamic Queue IF...
You limited teams in lower elo's up to silver to 3 players. And additionally put a rank cap back like you had with duo q. I don't like being in silver 2 having to go vs 2 plats or a plat and diamond on the enemy team just because mr joe bronze on the other team decided he wanted to get boosted. You want to keep 4-5 man queues? Fine but stick these bronze queueing with their diamond/plat friends in those elo's they gotta earn their boost. Not get an unequal advantage of stomping on lower elo players. The whole friend aspect of League is slowley killing it and making people more frustrated with ranked than ever before.
Oh not to mention it's likely that joe bronze and friends are using some voice comm so that's another HUGE advantage.