It does not seal anything it cuts, it seals anything it pierces. Itachi cut the heads off Oro's 8 Branches form and those were not sealed. You have to stab it through them and keep it there for a person to be sealed. Also I'm telling you I'm going to use it just the size of a katana. >> It would just be dumb for me not to be able to use this weapon because I am a Hyuuga.
The regular Kusanagi can cut through "anything" be levitated about and extend forever. Samehada is alive, acts as a sensor, can move on it's own, cuts through jutsu, restores your chakra, and can heal grievous wounds, you can even fuse with it if you own it long enough. I would argue Samehada is much more OP than the Totsuka Sword, and the Kusanagi is just as strong, if not more due to the incredible range of attack you can achieve with it.
In short, I'd have a very sharp sword that seals away people I impale with it... that's all. It does not seem like a big deal to me.