The 1,2,2 string does have some interesting properties (the last hit of that string to be precise) as keo-bas mentioned. You can only use it in the corner because the last hit will not land in a juggle anywhere else, the first two hits will float them just out of range for the last one to hit anywhere outside the corner.
The last hit of 1,2,2, when landed in a corner juggle, makes your opponent fall more slowly, it’s actually a fairly dramatic effect that you’ll pick up on right away, and it allows you to land a few different moves than you’d otherwise be able to. I’ve found Sektor to be a pretty damaging combo-character, he’s got some useful B&B combos that can go for big damage, so I do think playing around combos will work for him.
Still, no one has frame data, and there’s no true record function in training, so it’s been extremely hard for me to figure out how practical some of his stuff is. One situation I REALLY want to know the frames of is a whiffed uppercut. If you duck your opponents uppercut, are you guaranteed a 1,2,b+1? If so, Sektor is going to be a very dangerous character with some very damaging punishes.
Other than that, his b+3,4 is definitely going to be a great combo starter as well; it hit’s low and combos into his teleport punch for a nice, high launch. Just landing a teleport punch alone certainly allows you a B&B juggle, but landing it off of b+3,4 seems to give you a lot more height (and thus time) to play with when looking for a combo. f+4,4 into an EX teleport punch is going to yield big damage if you use it as your linker after your launch. It relaunches them and leaves you with nice spacing for a finisher.
As far as finishers, his missile does good damage as last hit but his flame thrower will reset them standing up --> that’s where I think another b+3,4 into combo is going to be some pretty deadly reset pressure.
Regardless, Sektor has very good combo damage IMO, at least from what I’ve been able to find with him, when compared to what I’ve been able to find with the other members of the cast I’ve experimented with so far. I really like that Scorpion and Subzero seem to be in line with everyone else, I was a little afraid they were going to have an edge on the rest of the cast. So far, the balancing seems to be pretty good.
The only thing I’ve heard otherwise is some of Sonya’s block strings into stance moves can be continuously chained together for repeated pressure and mix-ups in a way that obviously was not intended by the developers. However, I also heard it will be patched out or otherwise removed shortly. Supposedly there’s a patchless system in place, so only time (and testing) will tell.