Since the end is imminent, thoughts on my team:
Ness: Worth the 3, I think. Ness is versatile. Healing, status (how much you respect that is always a big judgement call), MT Damage, and some physical defense skills. I would say that early on Ness doesn't have the the mettle to be a 3, but he's partially a pick that you want to get to the end, when you suddenly get this awesomely defensive MT healer. Great syngergy with SS too since he has the durability to take a hit.
Nina 1: Damn well worth the 3. When Nina shines, she is fantastic. The speed and healing, decent early revival, and a few buff options are all great. Even better if you see her getting all her skills by endgame (I don't). Murdered floor 5 most alone, and was really great a lot of other floors.
Cielo: Oh god no. I mentioned at one point to Neph that Cielo needed a downgrade. He...needs it more than 0.5 point. He may need it more than 1 point. Take a look at all Ness' pluses. Cielo is similar except...blockable (and worse) damage, notably worse durability (Cielo is 90% before SS), and right, needs a specific seal stone to not be raped by status. He needs a seal stone with massive penalties to just stand even with most other dungeon participants. Of course, which those names, I didn't fully realize some of his skillset gaps. No revival, but lots of shitty buffs (Note: Buffs are great in game. Battles are long, so using buffs/debuffs that give little punch but stack 4 times works. HORRIBLE in dungeon though). Cielo was a complete project, but he was just so bad for a 3. His biggest plus was interrupting people with average speed healing, which you don't need a 3 for. This was a half Cielo/half SS project, and the Cielo part was just a bust.
Seifer: Well worth the points, albeit not as broken as I thought. The balance of MT healing hurting him a little, but still better than a 1. He was the smash, and with ITE/MT OHKO, he did it well. One thing I didn't realize pre dungeon though was that he was a tad slow (I knew he was fast at L99! Just...not at L10 apparentally), which hurt a tad.
Raja: Well worth the points, but bad synergy with SS. In pattern, I didn't realize that his Pdur was so bad even with shields. That said, Floor 2 I could basically just say that enemies had to kill Raja first or MT Defense Up would rape them. That alone made him good. Also, I know it's been done before, but Speed Raja would be absurd. Blazing fast MT Defense up that takes someone who is OHKOed by the average in the DL and makes him near average. And dungeon is mostly physical, although 100% MT Silence too of course. So abusable that I almost feel that he shouldn't be a 1 for that alone (Or alternately, Speed is the seal stone that you want to abuse!)
Status Symbol: I built my team as a project to see if this could work at all. The good is that it just devoured floors 4 and 5 and a few evil fights in 6. I doubt I would have gotten past 4 or 5 otherwise because of status. Of course, without the seal stone, I would have then picked people who had some blockers. The bad is that it comes with pretty nasty penalties that are always in effect, and until 4, it's a really, really big liability. I would say that you can make it function to a degree, but it's not a good sealstone. Sometimes getting a team rolling those first few floors can be the biggest challenge, and that's where SS hurts the most.