Brackets was clearly worst idea to do with solo ranked and it was obvious that it will absolutely kill games in upper bracket (altho ppl report that quality of matches did increase) and create a elo hell for lower one, making it impossible for those who played many games to get out of there EVER. For me personally, the time im able (and comfortable! could of course ruin either work or sleep) to play i have 0 matches in upper bracket since its introduced...

I guess quality of matches for solo ranked is incredibly arrogant expectation and there should be close to none. Solo ranked should just pop, more pops the better. It doesn't mean tho that matchmaking should not exist at all (its another topic).
Formal restrictions are of course is also the other matter. I previously was absolutely sure that general skill level of average RoR players is much higher than what most of us observe in solo ranked matches. I feel that tweaks in the system of "entry ticket" should be made.
We all know who's main concern was quality of matches so i suppose system will not find balance around one person interests.
Want good teammates? Group ranked/challenge system is waiting for you!
Altho restrictions could be kinda tuned, i guess it would be better if it would be something like the following:
- vanq/opp and rr70+ requirement to play solo ranked
- no requirement for group ranked/challenge
- get rid of MMR (no point to use anykind of bayesian stuff with ~800-1000 ppl online total on eu prime and of which only 300 chars played ~50 games, so i can assume its ~100 active players in rankeds)
- further reduce gear price by half so those who want their vanq/opp 2.0 (difference in stats are close to none existent, its just cloak opens up more mix&matches opportunities, 7p bonuses are very interesting but with current gear price none would bother to test them out) will get it and stop ruin games for other (active ~100 players will stay anyways cause those are there for fighting not rewards and those who are for tali or bis event slot will still play low amount of games weekly, thus pure gear grinders/zerg surfers who are usually hugely skill lacking will go)
- as a criteria of matchmaking simple win/loss ratio could be used, but in a way like just make a set of exclusions e.g. dont match 80% winrate with 30% (thats the hard part, criterias are always incredibly difficult to make fair enough, but i do believe this would be much better than trying to fit the shoes with mmr for 100 folks), for a qualification process could count newcomers as 50% (or make it dynamic, so 50% only for first game)