I wouldn't be speaking about Samus being good unless I used her in tourneys a lot and saw the results for myself, which I do. Against Marth and Meta Knight, bombs are amazing. This almost nullifies their ground approaches and allows you to keep pegging them with uncharged shots, and power missiles. How do I know this? Because I do it. Yes, going into the air against Marth is a bad idea, but the best thing about Samus is that she is adaptable as hell and has a wide variety of strategies against different characters. I would actually say that bombs are more precious in the fight against MK ad Marth than zair, because they are both fast enough to get under the zair most of the time.
1. Her projectile game is fine.
2. Her speed is also fine. Not slow in the least, and If you are a good Samus player then you know how to speed her up more. Check her running speed compared to the rest of the cast and see if it is really "slow"
3. KO power, not great. Off-stage combat + spike/gimping is amazing. Learn how to kill your opponent quicker given your advantages instead of complaining about ko power. Most of my kills with Samus now happen between 80% and 120%, and given the fact that she does a lot of damage per hit, thats pretty ****ing good.
A guy at this last big tourney asked me "So who do you main?" When I told him that I mained Samus, he laughed and said "Wow, really? I thought she was horrible now?" I was just like "Yeah, she sucks" and then proceeded to **** every Marth and MK i came across the entire day.
What I mean is that she is potentially high tier material, not that she is going to make high tier. The tier list isn't going to be nearly as important in Brawl because there are so many more characters, some of which are just going to be more unpopular than others. In tourneys I see mostly MK. This means that MK has a higher chance of winning simply because so many people use him, not because he CANT be beaten. Samus is a character that only dedicated people are going to use in tourney. This might put her low on the tier list, but that doesnt mean she CANT make high tier based on her character. Lets get that straight.