@taichokage: If he floats that high he can't use his own attack on Law unless he is in release for in which case Law will be faster. XD I have honestly never seen a battle in Bleach where the captains or villains just flew thousands of feet into the air and just trolled there for the whole fight, even Starkk got up close. As for the fight starts Law could use the Room, it's not know if other people's powers even work while inside, either way, I don't think the properties of the room are that simple. Barragan can't just rot away a power like that, it's like saying he can rot away Kidd's magnetism or Dio's time stop or Haki, or Tsukuyomi or something like that. I give this to Law since his power works at a greater distance and being fast enough to avoid Barragan when he starts to get close, not to mention his sorta gravity reverse thing he did on that ship, so that will trip him up, as well as being smarter too.
@taichokage: We are never told if that's true or not, we have no idea if the Room is energy based, it's the power of a fruit, it's more like a dimension or area. The Room is more or less like the 8 Trigrams, if you are in it, you are in range of Law's ability. It's not something you can age away, you are mistaking Law's ability for a ki barrier or kido blast, which it is not. The only things I really saw Barragan dilate were Soi fon's simple and relatively slow kick and a few other minor things outside his released form. Also Barragan can only rot away things gradualy, not instantly, for example if you throw a giant meteor at him, he would only be able to rot away a small portion before the rest hits him, this also means the speed of the attack comes into play as well, Law's rooms cover's the desired amount of space in almost no time at all, and it only takes a seconds or two for him to swing around his sword and mess someone's body up. Barragan can quickly rot away a fist coming at him or a sword slash, and MAYBE a normal sized kido/cero. But to completely annihilate Law's room before Law can use it's effect is kinda silly given what we has seen him do.
Besides, a normal human is capable of seeing Barragan's effect at work, I'm sure someone as fast as Law can act before it get's rid of the Room (Assuming it can, for the sake of argument) Close match, but I say Law.